View Filing Data

Condensed Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 248	$ 278
Restricted short-term investments	65	65
Accounts receivable	111,023	93,406
Deferred income taxes	34,252	32,342
Derivative instruments	3,129	2,742
Prepaid expenses and other	15,847	14,033
Total current assets	164,564	142,866
Oil and gas properties (successful efforts basis), buildings and equipment, net	2,959,386	2,655,792
Derivative instruments	1,418	2,054
Other assets	34,939	37,904
TOTAL ASSETS	3,160,307	2,838,616
Current liabilities:
Accounts payable	105,175	106,459
Revenue and royalties payable	33,492	37,812
Accrued liabilities	29,606	36,234
Line of credit	12,700	5,300
Derivative instruments	60,432	84,846
Total current liabilities	241,405	270,651
Long-term liabilities:
Deferred income taxes	362,939	329,207
Senior secured revolving credit facility	395,000	170,000
8.25% Senior subordinated notes due 2016	200,000	200,000
10.25% Senior notes due 2014, net of unamortized discount of $9,702 and $11,035, respectively	440,298	438,965
6.75% Senior notes due 2020	300,000	300,000
Asset retirement obligation	56,885	53,443
Derivative instruments	46,470	33,526
Other long-term liabilities	18,136	18,271
Total long-term liabilities	1,819,728	1,543,412
Shareholders' equity:
Preferred stock, $0.01 par value, 2,000,000 shares authorized; no shares outstanding
Capital stock, $0.01 par value:
Capital in excess of par value	338,397	327,369
Accumulated other comprehensive loss	(24,761)	(43,806)
Retained earnings	785,003	740,458
Total shareholders' equity	1,099,174	1,024,553
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	3,160,307	2,838,616
Class A
Capital stock, $0.01 par value:
Common Stock	517	514
Class B
Capital stock, $0.01 par value:
Common Stock	$ 18	$ 18

Condensed Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2011	Dec. 31, 2010
10.25% Senior notes due 2014, unamortized discount (in dollars)	$ 9,702	$ 11,035
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares outstanding	0	0
Class A
Capital stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common Stock, shares authorized	100,000,000	100,000,000
Common Stock, shares issued	51,604,476	51,426,232
Common Stock, shares outstanding	51,604,476	51,426,232
Class B
Capital stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common Stock, shares authorized	3,000,000	3,000,000
Common Stock, shares issued	1,797,784	1,797,784
Common Stock, shares outstanding	1,797,784	1,797,784
Common Stock, liquidation preference (in dollars)	$ 899	$ 899
8.25% Senior subordinated notes due 2016.
Interest rate on debt instrument (as a percent)	8.25%	8.25%
10.25% Senior notes due 2014
Interest rate on debt instrument (as a percent)	10.25%	10.25%
6.75% Senior notes due 2020
Interest rate on debt instrument (as a percent)	6.75%	6.75%

Condensed Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
Condensed Statements of Operations - USD ($) $ in Thousands	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
REVENUES
Sales of oil and gas	$ 230,760	$ 151,525	$ 418,149	$ 299,332
Sales of electricity	7,964	7,928	14,376	17,861
Gas marketing	3,985	5,004	7,670	13,276
Settlement of Flying J bankruptcy claim		21,992		21,992
Interest and other income, net	803	1,796	931	1,960
TOTAL REVENUES	243,512	188,245	441,126	354,421
EXPENSES
Operating costs - oil and gas production	58,780	46,452	115,863	93,488
Operating costs - electricity generation	6,891	7,839	13,004	17,509
Production taxes	8,350	5,064	15,741	10,269
Depreciation, depletion & amortization - oil and gas production	51,967	43,703	104,076	79,609
Depreciation, depletion & amortization - electricity generation	491	793	992	1,588
Gas marketing	3,674	4,357	7,190	12,142
General and administrative	15,910	12,155	32,201	25,990
Interest	17,712	16,340	33,367	33,788
Realized and unrealized (gain) loss on derivatives, net	(91,808)	(56,057)	35,708	(57,661)
Gain on purchase			(1,046)
Transaction costs on acquisitions		1,908		2,635
Dry hole, abandonment, impairment and exploration	310	266	423	1,636
Bad debt recovery		(38,508)		(38,508)
TOTAL EXPENSES	72,277	44,312	357,519	182,485
Earnings before income taxes	171,235	143,933	83,607	171,936
Income tax provision	66,069	54,910	30,938	65,244
Net earnings	$ 105,166	$ 89,023	$ 52,669	$ 106,692
Basic net earnings per share (in dollars per share)	$ 1.93	$ 1.65	$ 0.97	$ 2.01
Diluted net earnings per share (in dollars per share)	1.90	1.64	0.95	2.00
Dividends per share (in dollars per share)	$ 0.075	$ 0.075	$ 0.15	$ 0.15

Condensed Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
Condensed Statements of Cash Flows - USD ($) $ in Thousands	Jun. 30, 2011	Jun. 30, 2010
Cash flows from operating activities:
Net earnings	$ 52,669	$ 106,692
Depreciation, depletion and amortization	105,068	81,197
Gain on purchase	(1,046)
Amortization of debt issuance costs and net discount	4,205	4,218
Dry hole and impairment	298	1,428
Derivatives	19,496	(46,110)
Stock-based compensation expense	5,439	5,008
Deferred income taxes	19,572	61,142
Other, net	674
Cash paid for abandonment	(864)	(1,535)
Allowance for bad debt		(38,508)
Change in book overdraft	4,022	2,007
Changes in operating assets and liabilities:
Accounts receivable	(18,543)	(27,950)
Inventories, prepaid expenses, and other current assets	(1,813)	(5,226)
Accounts payable and revenue and royalties payable	24,044	(2,687)
Accrued interest and other accrued liabilities	(6,699)	(4,807)
Net cash provided by operating activities	206,522	134,869
Cash flows from investing activities:
Exploration and development of oil and gas properties	(271,433)	(135,038)
Property acquisitions	(145,461)	(150,674)
Capitalized interest	(18,664)	(13,054)
Net cash used in investing activities	(435,558)	(298,766)
Cash flows from financing activities:
Proceeds from issuances on line of credit	243,300	159,200
Repayments of borrowings under line of credit	(235,900)	(155,900)
Long-term borrowings under credit facility	357,500	165,000
Repayments of long-term borrowings under credit facility	(132,500)	(227,000)
Financing obligation	(185)	(169)
Debt issuance costs	(677)
Dividends paid	(8,124)	(8,083)
Proceeds from issuance of common stock, net		224,313
Proceeds from stock option exercises	3,415	1,156
Excess income tax benefit and other	2,177	308
Net cash provided by financing activities	229,006	158,825
Net decrease in cash and cash equivalents	(30)	(5,072)
Cash and cash equivalents at beginning of period	278	5,311
Cash and cash equivalents at end of period	248	239
Noncash investing activities:
(Decrease) increase in accrued capital expenditures	(32,781)	13,486
Increase in asset retirement obligation	$ 1,642	$ 1,860

Condensed Statement of Shareholders' Equity - 6 months ended Jun. 30, 2011 - USD ($) $ in Thousands	Total	Capital in Excess of Par Value	Retained Earnings	Accumulated Other Comprehensive Loss	Comprehensive Income	Class A Common Stock	Class B Common Stock
Balances at Dec. 31, 2010	$ 1,024,553	$ 327,369	$ 740,458	$ (43,806)		$ 514	$ 18
Increase (Decrease) in Shareholders' Equity
Stock options and restricted stock issued	3,415	3,412				3
Stock based compensation expense	5,439	5,439
Income tax effect of stock option exercises	2,177	2,177
Dividends ($0.15 per share)	(8,124)		(8,124)
Comprehensive earnings:
Net earnings	52,669		52,669		$ 52,669
Amortization of Accumulated other comprehensive loss related to de-designated hedges, net of income tax benefit of $11,673	19,045			19,045	19,045
Total comprehensive earnings	71,714				$ 71,714
Balances at Jun. 30, 2011	$ 1,099,174	$ 338,397	$ 785,003	$ (24,761)		$ 517	$ 18

Condensed Statement of Shareholders' Equity (Parenthetical) $ in Thousands	6 Months Ended
	Jun. 30, 2011 USD ($) $ / shares
Condensed Statement of Shareholders' Equity
Dividends per share (in dollars per share) \| $ / shares	$ 0.15
Amortization of Accumulated other comprehensive loss related to de-designated hedges, income tax benefit \| $	$ 11,673

Basis of Presentation

6 Months Ended

Jun. 30, 2011

Basis of Presentation

Basis of Presentation

1. Basis of Presentation

These Condensed Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) for interim financial reporting. All adjustments which are, in the opinion of management, necessary to fairly state Berry Petroleum Company's (the Company) Condensed Financial Statements have been included herein. Interim results are not necessarily indicative of expected annual results because of the impact of fluctuations in prices received for oil and natural gas, as well as other factors. In the course of preparing the Condensed Financial Statements, management makes various assumptions, judgments and estimates to determine the reported amounts of assets, liabilities, revenues and expenses, and in the disclosures of commitments and contingencies. Changes in these assumptions, judgments and estimates will occur as a result of the passage of time and the occurrence of future events, and, accordingly, actual results could differ from amounts previously established.

The Company's Condensed Financial Statements have been prepared on a basis consistent with the accounting principles and policies reflected in the Company's audited financial statements as of and for the year ended December 31, 2010. The year-end Condensed Balance Sheet was derived from audited Financial Statements included in such report, but does not include all disclosures required by GAAP.

Certain amounts in the prior year financial statements have been reclassified to conform to the 2011 financial statement presentation. The Company increased Comprehensive earnings for the three months ended March 31, 2010 by $6.8 million to reflect the correction of a prior period error. The Company has concluded that the presentation error was immaterial to the previously filed financial statements.

The Company's cash management process provides for the daily funding of checks as they are presented to the bank. Included in accounts payable at June 30, 2011 and December 31, 2010 are $20.3 million and $16.3 million, respectively, representing outstanding checks in excess of the bank balance (book overdraft).

Recent Accounting Standards

In May 2011, the FASB issued Accounting Standards Update (ASU) No. 2011-04 Amendments to Achieve Common Fair Value Measurement and Disclosure Requirements in US GAAP and IFRSs. The ASU amends previously issued authoritative guidance and requires new disclosures, clarifies existing disclosures and is effective for interim and annual periods beginning after December 15, 2011. The amendments change requirements for measuring fair value and disclosing information about those measurements. Additionally, the ASU clarifies the FASB's intent regarding the application of existing fair value measurement requirements and changes certain principles or requirements for measuring fair value or disclosing information about its measurements. For many of the requirements, the FASB does not intend the amendments to change the application of the existing Fair Value Measurements guidance. The Company anticipates the guidance will have no impact on its financial position or results of operations.

In June 2011, the FASB issued ASU No. 2011-05 Presentation of Comprehensive Income. The ASU amends previously issued authoritative guidance and is effective for fiscal years, and interim periods within those years, beginning after December 15, 2011. These amendments remove the option under current U.S. GAAP to present the components of other comprehensive income as part of the statements of changes in stockholder's equity. Because the ASU requires only a change in disclosures, the guidance will have no impact on the Company's financial position or results of operations.

- Definition

The entire disclosure for organization, consolidation and basis of presentation of financial statements disclosure.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 51
-Paragraph 2-6
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Name Statement of Position (SOP)
-Publisher AICPA
-Number 94-6
-Paragraph 10
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Name FASB Interpretation (FIN)
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-Number 46R
-Paragraph 4, 14, 15
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6359553&loc=d3e288-107754

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Reference 7: http://www.xbrl.org/2003/role/presentationRef
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Reference 16: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Staff Position (FSP)
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+ Details

Acquisitions

6 Months Ended

Jun. 30, 2011

Acquisitions

Acquisitions

2. Acquisitions

On May 25, 2011, the Company acquired interests in producing properties on approximately 6,000 net acres in the Wolfberry trend in the Permian for an aggregate purchase price of $129.4 million, including an initial purchase price of $128.5 million and customary post-closing adjustments of approximately $0.9 million (the Wolfberry Acquisition). The Wolfberry Acquisition had an effective date of March 1, 2011, with operations from March 1, 2011 through May 24, 2011 resulting in purchase price adjustments. The acquisition was financed using the Company's senior secured revolving credit facility (Credit Agreement). The Company operates 98% of and has an average 93% working interest (70% net revenue interest) in the properties acquired in the Wolfberry Acquisition.

Revenues of $1.4 million and operating costs of $0.3 million from the acquired properties from May 25, 2011 to June 30, 2011 have been included in the accompanying Condensed Statements of Operations.

The following table summarizes the consideration paid and the amounts of the assets acquired and liabilities assumed as of May 25, 2011:

		(in thousands)

Consideration paid to sellers:
Cash consideration		$	129,376

Recognized amounts of identifiable assets acquired and liabilities assumed:
	Proved developed and undeveloped properties		129,631
	Asset retirement obligation		(119	)
	Other liabilities assumed		(136	)

Total identifiable net assets		$	129,376

In March, April and November 2010, the Company completed three separate acquisitions of producing properties located in the Wolfberry trend in the Permian for an aggregate purchase price of approximately $327 million (the Permian Acquisitions). The Permian Acquisitions were financed with net proceeds from the issuance in January 2010 of 8 million shares of the Company's Class A Common Stock, cash generated from operations and net proceeds from the issuance in November 2010 of $300 million aggregate principal amount of the Company's 6.75% senior notes due in November 2020 (2020 Notes).

The Wolfberry Acquisition and the Permian Acquisitions qualify as business combinations and, as such, the Company estimated the fair value of each property as of each acquisition date (the date on which the Company obtained control of the properties). The fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Fair value measurements also utilize assumptions of market participants. The Company used a discounted cash flow model based on an income approach and made market assumptions as to future commodity prices, projections of estimated quantities of oil and natural gas reserves, expectations for timing and amount of future development and operating costs, projections of future rates of production, expected recovery rates and risk adjusted discount rates. Due to the unobservable nature of the inputs, business combinations are deemed to use Level 3 inputs.

In the first quarter of 2011, the Company recorded a $1.0 million gain (net of deferred income taxes of $0.7 million) in conjunction with usual and customary post-closing adjustments to the purchase price of the November 2010 Permian acquisition. The gain was recorded in the Condensed Statements of Operations under the caption Gain on purchase.

The following table summarizes the consideration paid to the sellers and the amounts of the assets acquired and liabilities assumed in the Permian Acquisitions:

		(in thousands)

Consideration paid to sellers:
Cash consideration		$	327,032

Recognized amounts of identifiable assets acquired and liabilities assumed:
	Proved developed and undeveloped properties		332,214
	Other assets acquired		342
	Asset retirement obligation		(3,498	)
	Deferred income tax liability		(647	)
	Other liabilities assumed		(333	)

Total identifiable net assets		$	328,078

- Definition

The entire disclosure for a business combination (or series of individually immaterial business combinations) completed during the period, including background, timing, and recognized assets and liabilities. The disclosure may include leverage buyout transactions (as applicable).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Emerging Issues Task Force (EITF)
-Number 88-16
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 141
-Paragraph 51, 52
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Name Statement of Financial Accounting Standard (FAS)
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-Paragraph F4
-Subparagraph e

Reference 4: http://www.xbrl.org/2003/role/presentationRef
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+ Details

Debt

6 Months Ended

Jun. 30, 2011

Debt

Debt

3. Debt

Short-Term Line of Credit

The Company has an unsecured uncommitted money market line of credit (Line of Credit) with borrowing capacity of up to $40.0 million for a maximum of 30 days. As of June 30, 2011 and December 31, 2010 there were $12.7 million and $5.3 million in outstanding borrowings under the Line of Credit, respectively. Interest on amounts borrowed is charged at LIBOR plus a margin of approximately 1.4%. The outstanding borrowings under the Line of Credit at June 30, 2011 and December 31, 2010 had weighted average interest rates of 1.6% and 1.7%, respectively.

Senior Secured Revolving Credit Facility

On April 13, 2011, the Company entered into an amendment to its Credit Agreement (the Amendment). The Amendment extended the maturity date of the Credit Agreement to May 13, 2016 and increased the borrowing base from $875 million to $1.4 billion. Lender commitments remain unchanged at $875 million. In addition, the Amendment reduced (i) the LIBOR margin to between 1.50% and 2.50% based on the ratio of credit outstanding to the borrowing base, (ii) the prime rate margin to between 0.50% and 1.50% based on the ratio of credit outstanding to the borrowing base, and (iii) the annual commitment fee on the unused portion of the Credit Agreement to between 0.35% and 0.50%. The Amendment also provides the right for the Company to refinance its 10.25% senior notes due in 2014 (2014 Notes) and its 8.25% senior notes due in 2016 (2016 Notes) with similar notes or to retire the 2014 Notes or the 2016 Notes using available borrowing under the Credit Agreement subject to certain leverage and liquidity tests.

As of June 30, 2011 and December 31, 2010, there were $395 million and $170 million in outstanding borrowings under the Credit Agreement, respectively. The Company's total outstanding debt at June 30, 2011 under the Line of Credit and Credit Agreement was $408 million, with an additional $23 million in letters of credit issued under the Credit Agreement, leaving $444 million in borrowing capacity available.

The maximum amount available is subject to semi-annual redeterminations of the borrowing base based on the value of the Company's proved oil and natural gas reserves in April and October of each year in accordance with the lenders' customary procedures and practices. The Company and the banks each have the unilateral right to one additional redetermination each year. The Credit Agreement is collateralized by the Company's oil and natural gas properties.

The Credit Agreement contains restrictive covenants that may limit the Company's ability to, among other things, incur additional indebtedness, sell assets, make loans to others, make investments, enter into mergers, enter into hedging contracts, incur liens and engage in certain other transactions without the prior consent of its lenders. The Credit Agreement contains covenants which, among other things, require the Company to maintain the following ratios: (i) an interest coverage ratio, as defined in the credit agreement, of 2.75 to 1.0 and (ii) a minimum current ratio, as defined in the Credit Agreement, of 1.0 to 1.0. The Company is currently in compliance with all financial covenants and has complied with all financial covenants for all prior periods.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References + Details

Income Taxes

6 Months Ended

Jun. 30, 2011

Income Taxes

Income Taxes

4. Income Taxes

The effective income tax rate for the three months ended June 30, 2011 and 2010 was 38.6% and 38.1%, respectively. The increase in the effective income tax rate in the three months ended June 30, 2011 compared to the of the three months ended June 30, 2010 is primarily due to the income tax effect of nondeductible stock compensation expense in the three months ended June 30, 2011.

The effective income tax rate for the six months ended June 30, 2011 and 2010 was 37.0% and 37.9%, respectively. The decrease in the effective income tax rate in the six months ended June 30, 2011 compared to the six months ended June 30, 2010 is primarily due to a change in state deferred income taxes as a result of acquisitions, which change the mix of state apportionments. The Company's estimated annual effective income tax rate varies from the 35% federal statutory rate due to the effects of state income taxes and estimated permanent differences (i.e. differences between book earnings and tax earning that are not expected to reverse in future periods).

As of June 30, 2011, the Company had a gross liability for uncertain income tax benefits of $5.3 million, which if recognized would affect the effective income tax rate. There have been no significant changes to the calculation of uncertain income tax benefits during 2011. The Company recognized potential accrued interest and penalties related to unrecognized income tax benefits in income tax expense during the three months ended June 30, 2011, which is consistent with the recognition of these items in prior periods. The Company has accrued approximately $0.9 million and $0.8 million of interest related to its uncertain income tax positions as of June 30, 2011 and December 31, 2010, respectively. The Company estimates that it is reasonably possible that the balance of unrecognized income tax benefits as of June 30, 2011 could decrease by a maximum of $1.9 million in the next 12 months due to the expiration of statutes of limitation and audit settlements.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 08
-Paragraph h
-Article 4

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 136, 172
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 43, 44, 45, 46, 47, 48, 49
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32718-109319

Reference 5: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32639-109319

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h))
-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32559-109319

+ Details

Earnings Per Share and Comprehensive Earnings

6 Months Ended

Jun. 30, 2011

Earnings Per Share and Comprehensive Earnings

Earnings Per Share and Comprehensive Earnings

5. Earnings Per Share and Comprehensive Earnings

Basic earnings per share is calculated by dividing earnings available to common shareholders by the weighted average shares outstanding—basic during each period. Diluted earnings per share is calculated by dividing earnings available to common shareholders by the weighted average shares outstanding—dilutive, which includes the effect of potentially dilutive securities. Potentially dilutive securities consist of unvested restricted stock awards and outstanding stock options.

The two-class method of computing earnings per share is required for those entities that have participating securities. The two-class method is an earnings allocation formula that determines earnings per share for participating securities according to dividends declared (or accumulated) and participation rights in undistributed earnings. Unvested restricted stock issued prior to January 1, 2010 under the Company's equity incentive plans has the right to receive non-forfeitable dividends, participating on an equal basis with common stock, and thus are classified as participating securities. Unvested restricted stock issued subsequent to January 1, 2010 under the Company's equity incentive plans does not participate in dividends. Stock options issued under the Company's equity incentive plans do not participate in dividends.

The following table shows the computation of basic and diluted earnings per share for the three and six months ended June 30, 2011 and 2010:

	Three Months Ended June 30,				Six Months Ended June 30,

(in thousands, except per share data)	2011		2010		2011		2010
Net earnings	$	105,166	$	89,023	$	52,669	$	106,692
Less: earnings allocable to participating securities		1,012		1,713		544		2,133

Earnings available for common shareholders	$	104,154	$	87,310	$	52,125	$	104,559
Basic earnings per share	$	1.93	$	1.65	$	0.97	$	2.01

Diluted earnings per share	$	1.90	$	1.64	$	0.95	$	2.00

Weighted average shares outstanding—basic		54,004		52,965		53,936		52,027
Add: Dilutive effects of stock options and RSUs		704		448		755		380

Weighted average shares outstanding—dilutive		54,708		53,413		54,691		52,407

All options to purchase shares were included in the diluted earnings per share calculation for the three and six months ended June 30, 2011. Options to purchase 0.8 million shares and 1.2 million shares were not included in the diluted earnings per share calculation for the three and six months ended June 30, 2010, respectively, because their effect would have been anti-dilutive.

Comprehensive earnings

Comprehensive earnings is a term used to refer to net earnings plus other comprehensive earnings. Other comprehensive earnings is comprised of revenues, expenses, gains, and losses that, under GAAP, are reported as separate components of shareholders' equity instead of net earnings. The components of other comprehensive earnings were as follows:

	Three months ended June 30,				Six months ended June 30,

(in thousands)	2011		2010		2011		2010
Net earnings	$	105,166	$	89,023	$	52,669	$	106,692
Amortization of Accumulated other comprehensive loss related to de-designated hedges, net of income tax benefits of $5,837, $2,478, $11,673, and $4,563, respectively		9,522		4,044		19,045		7,444

Comprehensive earnings	$	114,688	$	93,067	$	71,714	$	114,136

Asset Retirement Obligation

6 Months Ended

Jun. 30, 2011

Asset Retirement Obligation

Asset Retirement Obligation

6. Asset Retirement Obligation

The following table summarizes the activity for the Company's asset retirement obligation (ARO) for the six months ended June 30, 2011 and 2010:

	Six months ended June 30,

(in thousands)	2011			2010
Beginning balance at January 1	$	53,443		$	43,487
Liabilities incurred		1,642			1,860
Liabilities settled		(864	)		(1,534	)
Liabilities assumed		119			3,309
Accretion expense		2,545			2,191

Ending balance at June 30	$	56,885		$	49,313

ARO reflects the estimated present value of the amount of dismantlement, removal, site reclamation and similar activities associated with the Company's oil and gas properties. Inherent in the fair value calculation of ARO are numerous assumptions and judgments including the ultimate settlement amounts, inflation factors, credit adjusted discount rates, timing of settlement and changes in the legal, regulatory, environmental and political environments. To the extent future revisions to these assumptions impact the fair value of the existing ARO liability, a corresponding adjustment is made to the oil and gas property balance.

Equity Incentive Compensation Plans

6 Months Ended

Jun. 30, 2011

Equity Incentive Compensation Plans

Equity Incentive Compensation Plans

7. Equity Incentive Compensation Plans

Stock-based compensation is measured at the grant date based on the value of the awards, and the fair value is recognized on a straight-line basis over the requisite service period (usually the vesting period).

Total compensation cost recognized in the Statements of Operations for the grants under the Company's equity incentive compensation plans was $2.2 million and $1.8 million during the three months ended June 30, 2011 and 2010, respectively, and $5.1 million and $4.1 million during the six months ended June 30, 2011 and 2010, respectively.

Stock Options

The following table summarizes stock option activity for the six months ended June 30, 2011:

				Weighted Average Exercise Price		Aggregate Intrinsic Value (in thousands)(1)

Outstanding at January 1, 2011		2,017,225		$	25.87	$	35,974	1,884,937
	Granted	89,865			48.50
	Exercised	(229,685	)		14.93
	Cancelled/expired	—			—

Outstanding at June 30, 2011		1,877,405		$	28.29	$	46,637	1,656,002

(1): The intrinsic value of a stock option is the amount by which the market value of the underlying stock at the end of the related period exceeds the exercise price of the option.

In March 2011, 89,865 stock options were granted under the 2010 Equity Incentive Plan to certain executive officers and other officers of the Company with exercise prices equal to the closing market price of the Company's Class A Common Stock on the grant date. These stock options generally vest ratably over a four-year service period from the grant date and are exercisable immediately upon vesting through the tenth anniversary of the grant date.

The fair value of each option granted was estimated using the Black-Scholes option pricing model. The following assumptions were used to compute the weighted average fair market value of options granted:



Expected volatility	45.00	%
Risk-free interest rate	2.54	%
Dividend yield	0.62	%
Expected term (in years)	6.0

As of June 30, 2011, there was $1.7 million of total unrecognized compensation cost related to outstanding stock options. This cost is expected to be recognized over 3.8 years.

Restricted Stock Units

The following table summarizes restricted stock unit (RSU) activity for the six months ended June 30, 2011:

				Weighted Average Grant Date Fair Value		Vest Date Fair Value (in thousands)

Outstanding at January 1, 2011		857,360		$	19.67
	Granted	153,240			47.78
	Issued	(14,515	)		38.69	$	678
	Canceled/expired	(3,388	)		25.47

Outstanding at June 30, 2011(1)(2)		992,697		$	23.70

(1): The balance outstanding includes 30,544 RSUs granted to the non-employee Directors that are 100% vested at date of grant but are subject to a deferral election before the corresponding shares are issued.
(2): The balance outstanding includes 294,767 RSUs granted to executive officers and other officers that have vested in accordance with the RSU agreement, but are subject to a deferral election before the corresponding shares are issued.

As of June 30, 2011, there was $10.5 million of total unrecognized compensation cost related to RSUs granted. This cost is expected to be recognized over 3.8 years.

Performance Share Program

The following table summarizes performance share award activity for the six months ended June 30, 2011:

			Weighted Average Grant Date Fair Value		Vest Date Fair Value (in Thousands)

Outstanding at January 1, 2011		103,794	$	31.20
	Granted	65,620		51.86
	Issued	—		—	$	—
	Canceled/expired	—		—

Outstanding at June 30, 2011		169,414	$	39.20

In March 2011, 65,620 RSUs that are subject to internal performance metrics and market based vesting criteria in addition to a three-year service condition (performance shares), were granted to executive officers and other officers. The ultimate vesting of awards is contingent upon meeting the established criteria. From January 1, 2011 to December 31, 2013, the Company must maintain an interest coverage ratio of at least 2.5 to 1.0. The number of performance share awards that ultimately vest is based on two equally weighted performance factors: (i) compounded annual production growth as measured by average annual barrels of oil equivalent per day (BOE/D) and (ii) total shareholder return as compared to the Company's defined peer group for years 2011-2013.

For the portion of performance share awards subject to internal performance metrics, the grant date fair value was determined by reference to the closing price of a share of Class A Common Stock on the date of grant. The Company recognizes compensation expense when it becomes probable that these conditions will be achieved. However, any such compensation expense recognized is reversed if vesting does not actually occur.

For the portion of performance share awards subject to market based vesting criteria, the grant date fair value was estimated using a Monte Carlo valuation model. The Monte Carlo model is based on random projections of stock price paths and must be repeated numerous times to achieve a probabilistic assessment. Expected volatility was calculated based on the historical volatility of the Company's common stock, and the risk-free interest rate is based on U.S. Treasury yield curve rates with maturities consistent with the three-year vesting period. The key assumptions used in valuing the market-based restricted shares were as follows:



Number of simulations	100,000
Expected volatility	44	%
Risk-free rate	1.15	%

As of June 30, 2011, there was $2.3 million of total unrecognized compensation cost related to performance share awards granted. This cost is expected to be recognized over 2.5 years.

- Definition

The entire disclosure for compensation-related costs for equity-based compensation, which may include disclosure of policies, compensation plan details, allocation of equity compensation, incentive distributions, equity-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 123R
-Paragraph 64, 65, A240
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 93-6
-Paragraph 53
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 14

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 50
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6406099&loc=d3e25284-112666

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5444-113901

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 40
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6418621&loc=d3e17540-113929

+ Details

Derivative Instruments

6 Months Ended

Jun. 30, 2011

Derivative Instruments

Derivative Instruments

8. Derivative Instruments

The Company uses financial derivative instruments as part of its price risk management program to achieve a more predictable, economic cash flow from its oil and natural gas production by reducing its exposure to price fluctuations. The Company has entered into financial commodity swap and collar contracts to fix the floor and ceiling prices received for a portion of the Company's oil and natural gas production. The terms of the contracts depend on various factors, including management's view of future crude oil and natural gas prices, acquisition economics on purchased assets and future financial commitments. The Company periodically enters into interest rate derivative agreements to protect against changes in interest rates on its floating rate debt. For further discussion related to the fair value of the Company's derivatives see Note 9 to the Condensed Financial Statements.

As of June 30, 2011, the Company had commodity derivatives associated with the following volumes:



Oil Bbl/D:	20,020	19,000	13,000	2,000
Natural Gas MMBtu/D:	15,000	15,000	—	—

The Company entered into the following crude oil three-way collars during the six months ended June 30, 2011:

Term		Floor/Swap/Ceiling Prices

February 2011 - December 2013	1,000	$70.00 / $90.00 / $116.50
Full year 2012 and 2013	1,000	$70.00 / $90.00 / $120.00
Full year 2012 and 2013	1,000	$70.00 / $95.00 / $120.10
June 2011 - December 2014	1,000	$77.95 / $105.00 / $115.00
Full year 2012, 2013, and 2014	1,000	$80.00 / $107.00 / $119.60

Discontinuance of cash flow hedge accounting

Effective January 1, 2010, the Company elected to de-designate all of its commodity and interest rate derivative contracts that had been previously designated as cash flow hedges as of December 31, 2009. As a result, subsequent to December 31, 2009, the Company recognizes all gains and losses from changes in commodity derivative fair values immediately in earnings rather than deferring any such amounts in accumulated other comprehensive loss (AOCL). As a result of discontinuing hedge accounting on January 1, 2010, the fair values of the Company's open derivative contract designated as cash flow hedges as of December 31, 2009, less any ineffectiveness recognized, were frozen in AOCL and are reclassified into earnings as the original hedge transactions settle.

At December 31, 2010, AOCL consisted of $70.7 million ($43.8 million, net of income tax) of unrealized losses on commodity and interest rate contracts that had been previously designated as cash flow hedges. At June 30, 2011, AOCL consisted of $39.9 million ($24.8 million net of income tax) of unrealized losses on commodity and interest rate contracts that had been previously designated as cash flow hedges. During the three and six months ended June 30, 2011, $15.3 million ($9.5 million, net of income tax) and $30.7 million ($19.0 million, net of income tax), respectively, of non-cash amortization of AOCL related to de-designated hedges was reclassified from AOCL into earnings. The Company expects to reclassify into earnings from AOCL after-tax net losses of $21.5 million related to de-designated commodity and interest rate derivative contracts during the next 12 months.

The following tables detail the fair value of derivatives recorded on the Company's Condensed Balance Sheets, by category:

		June 30, 2011

		Derivative Assets			Derivative Liabilities
(in millions)		Balance Sheet Classification	Fair Value		Balance Sheet Classification	Fair Value
Current:
	Commodity	Derivative assets	$	3.1	Derivative liabilities	$	60.4
Long term:
	Commodity	Derivative assets		1.4	Derivative liabilities		46.5

Total derivatives			$	4.5		$	106.9

		December 31, 2010

		Derivative Assets			Derivative Liabilities
(in millions)		Balance Sheet Classification	Fair Value		Balance Sheet Classification	Fair Value
Current:
	Commodity	Derivative assets	$	2.7	Derivative liabilities	$	84.9
Long term:
	Commodity	Derivative assets		2.1	Derivative liabilities		33.5

Total derivatives			$	4.8		$	118.4

The table below summarizes the location and the amount of derivative instrument (gains) losses before income taxes reported in the Condensed Statements of Operations for the periods indicated (in millions):

		Three months ended June 30,						Six months ended June 30,

	Location of (Gain) Loss Recognized in Earnings	Three months ended June 30,						Six months ended June 30,
Description of (Gain) Loss	Location of (Gain) Loss Recognized in Earnings	2011			2010			2011		2010
Commodity
(Gain) loss reclassified from AOCL into earnings (amortization of frozen amounts)	Sales of oil and gas	$	14.9		$	4.1		$	29.5	$	6.9
(Gain) loss recognized in earnings (cash settlements and mark-to-market movements)	Realized and unrealized (gain) loss on derivatives, net		(91.8	)		(58.8	)		35.7		(63.7	)
Interest rate
(Gain) loss reclassified from AOCL into earnings (amortization of frozen amounts)	Interest	$	0.4		$	2.4		$	1.2	$	5.1
(Gain) loss recognized in earnings (cash settlements and mark-to-market movements)	Realized and unrealized (gain) loss on derivatives, net		—			2.7			—		6.0

Credit risk

The Company does not require collateral or other security from counterparties to support derivative instruments. However, the agreements with those counterparties typically contain netting provisions such that if a default occurs, the non-defaulting party can offset the amount payable to the defaulting party under the derivative contract with the amount due from the defaulting party. As a result of the netting provisions the Company's maximum amount of loss due to credit risk is limited to the net amounts due to and from the counterparties under the derivative contracts. The maximum amount of loss due to credit risk that the Company would have incurred if all counterparties to its derivative contracts failed to perform at June 30, 2011 was $4.5 million.

As of June 30, 2011, the counterparties to the Company's commodity derivative contracts consist of nine financial institutions. The Company's counterparties or their affiliates are also lenders under the Company's Credit Agreement. As a result, the counterparties to the Company's derivative agreements share in the collateral supporting the Company's Credit Agreement. The Company is not generally required to post additional collateral under derivative agreements.

Certain of the Company's derivative agreements contain provisions that require cross defaults and acceleration of those instruments to any material debt. If the Company were to default on any of its material debt agreements, it would be a violation of these provisions, and the counterparties to the derivative instruments could request immediate payment on derivative instruments that are in a net liability position at that time. As of June 30, 2011, the Company was in a net liability position with seven of the counterparties to the Company's derivative instruments, totaling $107 million. As of June 30, 2011, the Company's largest three counterparties accounted for 59% of the value of its total net derivative positions.

- Definition

The entire disclosure for the entity's entire derivative instruments and hedging activities. Describes an entity's risk management strategies, derivatives in hedging activities and non-hedging derivative instruments, the assets, obligations, liabilities, revenues and expenses arising therefrom, and the amounts of and methodologies and assumptions used in determining the amounts of such items.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 133
-Paragraph 45
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 133
-Paragraph 44
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
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-URI http://asc.fasb.org/extlink&oid=6887037&loc=d3e80784-113994

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-Name Accounting Standards Codification
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-Topic 815
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+ Details

Fair Value Measurements

6 Months Ended

Jun. 30, 2011

Fair Value Measurements

Fair Value Measurements

9. Fair Value Measurements

The authoritative guidance for fair value measurements establishes a three-tier fair value hierarchy, which prioritizes the inputs used to measure fair value. These tiers include: Level 1, defined as unadjusted quoted prices in active markets for identical assets or liabilities; Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs for use when little or no market data exists, therefore requiring an entity to develop its own assumptions.

A financial instrument's categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The Company's assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the classification of assets and liabilities within the fair value hierarchy. The fair value of all derivative instruments is estimated with industry-standard models that consider various assumptions, including quoted forward prices for commodities, time value, volatility factors and current market and contractual prices for the underlying instruments, as well as other relevant economic measures. The fair value of all derivative instruments is estimated using a combined income and market valuation methodology based upon forward commodity price and volatility curves. The curves are obtained from independent pricing services, and the Company has made no adjustments to the obtained prices. The pricing services publish observable market information from multiple brokers and exchanges. All valuations were compared against counterparty valuations to verify the reasonableness of prices. The Company also considers counterparty credit risk and its own credit risk in its determination of all estimated fair values. The Company has consistently applied these valuation techniques in all periods presented and believes it has obtained the most accurate information available for the types of derivative contracts it holds. The Company recognizes transfers between levels at the end of the reporting period for which the transfer has occurred.

Liabilities measured at fair value on a recurring basis

The following table sets forth by level within the fair value hierarchy the Company's net derivative liabilities that were measured at fair value on a recurring basis as of June 30, 2011 and December 31, 2010:

(in millions)		Total			Level 1		Level 2			Level 3

Commodity derivatives liability, net
	June 30, 2011	$	(102.4	)	$	—	$	(102.4	)	$	—
	December 31, 2010	$	(113.6	)	$	—	$	(11.8	)	$	(101.8	)

Changes in Level 3 fair value measurements

The table below includes a rollforward of the Condensed Balance Sheet amounts (including the change in fair value) for financial instruments classified by the Company within Level 3 of the fair value hierarchy. When a determination is made to classify a financial instrument within Level 3 of the fair value hierarchy, the determination is based upon the significance of the unobservable factors to the overall fair value measurement. Level 3 financial instruments typically include, in addition to the unobservable or Level 3 components, observable components (that is, components that are actively quoted and can be validated to external sources).

			Three months ended June 30,					Six months ended June 30,

(in millions)			2011		2010			2011			2010
Fair value liability, beginning of period			$	—	$	(34.5	)	$	(101.8	)	$	(26.0	)
	Transfers out of Level 3(1)			—		—			101.8			—
		Realized and unrealized gain included in earnings		—		41.2			—			41.9
	Settlements			—		(10.7	)		—			(19.9	)

Fair value liability, end of period			$	—	$	(4.0	)	$	—		$	(4.0	)

Total unrealized gain included in earnings related to financial assets and liabilities still on the Condensed Balance Sheet at June 30, 2011 and 2010			$	—	$	30.5		$	—		$	22.0

(1): During the first quarter of 2011, the inputs used to value oil collars, natural gas collars and natural gas basis swaps were directly or indirectly observable, and these instruments were transferred to level 2.

For further discussion related to the Company's derivatives see Note 8 to the Condensed Financial Statements.

Fair Market Value of Financial Instruments

The Company uses various assumptions and methods in estimating the fair values of its financial instruments. The carrying amounts of cash and cash equivalents and accounts receivable approximated their fair value due to the short-term maturity of these instruments. The carrying amount of the Company's credit facilities approximated fair value because the interest rates on the credit facilities are variable and could be at similar rates today. The fair values of the 2016 Notes, the 2014 Notes, and 2020 Notes were estimated based on quoted market prices. The fair values of the Company's derivative instruments and other investments are discussed above.

	June 30, 2011				December 31, 2010

(in millions)	Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
Line of credit	$	13	$	13	$	5	$	5
Senior secured revolving credit facility		395		395		170		170
8.25% Senior subordinated notes due 2016		200		208		200		210
10.25% Senior notes due 2014		440		513		439		518
6.75% Senior notes due 2020		300		300		300		303

	$	1,348	$	1,429	$	1,114	$	1,206

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 133
-Paragraph 44A, 44B
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 15C, 15D
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 15A
-Subparagraph a-d
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 15B
-Subparagraph a, b
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 3, 10, 14, 15
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 157
-Paragraph 32, 33, 34
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 159
-Paragraph 17-22, 27, 28
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
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+ Details

Dry hole, abandonment, impairment and exploration

6 Months Ended

Jun. 30, 2011

Dry hole, abandonment, impairment and exploration

Dry hole, abandonment, impairment and exploration

10. Dry hole, abandonment, impairment and exploration

For the three and six months ended June 30, 2011, the Company incurred dry hole, abandonment, impairment and exploration expense of $0.3 million and $0.4 million, respectively. During the three and six months ended June 30, 2010, the Company incurred dry hole, abandonment, impairment and exploration expense of $0.3 million and $1.6 million, respectively, which was primarily the result of mechanical failure encountered on one well in the Piceance. The well was abandoned in favor of drilling a replacement well from the same pad.

Commitments and Contingencies

6 Months Ended

Jun. 30, 2011

Commitments and Contingencies

Commitments and Contingencies

11. Commitments and Contingencies

Uinta Crude Oil Sales Contract

The Company is a party to a crude oil sales contract through June 30, 2013 with a refiner for the purchase of a minimum of 5,000 Bbl/D of its Uinta light crude oil. Pricing under the contract, which includes transportation and gravity adjustments, is at a fixed percentage of WTI. Gross oil production from the Company's Uinta properties averaged approximately 3,500 Bbl/D in the first six months of 2011. Due to the possibility of refinery constraints in the Utah region, it is possible that the loss of the Company's crude oil sales customer in Utah could impact the marketability of a portion of the Company's Utah crude oil volumes. See Item 1A. Risk Factors of the Company's Annual Report on Form 10-K for the year ended December 31, 2010 filed with the SEC on March 1, 2011.

E. Texas Gathering System

In July 2009, the Company closed on the financing of its E. Texas gas gathering system for $18.4 million in cash. The Company entered into concurrent long-term gas gathering agreements for the E. Texas production, which contained an embedded lease. The transaction was treated as a financing obligation. Accordingly, the $16.7 million net book value of the property is being depreciated over the remaining useful life of the asset and the cash received of $18.4 million was recorded as a financing obligation. A portion of the payments under the agreements are recorded as gathering expense and a portion as interest expense, with the balance being recorded as a reduction to the financing obligation. There are no minimum payments required under these agreements. For the three months ended June 30, 2011 and 2010, the Company incurred $1.4 million and $1.5 million, respectively, under the agreements. For the six months ended June 30, 2011 and 2010, the Company incurred $3.1 million and $2.6 million, respectively, under the agreements.

Carry and Earning Agreement

On January 14, 2011, the Company entered into an amendment relating to certain contractual obligations to a third party co-owner of certain Piceance assets in Colorado. The amendment waives the $0.2 million penalty for each well not spud by February 2011. The Company is obligated to pay the first $4.5 million of costs incurred by such third party in connection with the construction, on behalf of both the Company and such third party, of either an extension of an existing access road or a new access road. If by December 31, 2012 (which date may, under certain circumstances, be extended until December 31, 2014), the Company has not expended $9.0 million ($4.5 million of which would otherwise be such third party's responsibility) in road construction costs, then it will be obligated to pay the third party 50% of the difference between $12.0 million and the actual amount expended on road construction as of such date. In addition, the amendment extends the date by which the Company must complete its drilling obligations on the North Parachute property to January 31, 2020.

Legal Matters

COGCC Order—On April 21, 2011, the Company received a proposed Order Finding Violation from the Colorado Oil and Gas Conservation Commission ("COGCC") alleging that certain releases in late 2007 from a lined reserve pit located on a well pad in western Colorado violated COGCC regulations. Shortly thereafter, the Company entered into negotiations with the COGCC. While the Company denies that it violated any COGCC regulations in connection with the releases, on June 27, 2011, the COGCC approved and the Company later signed an Administrative Order on Consent under which the Company will pay $100,000, and fund a mutually acceptable public project in the amount of $73,000, in full satisfaction of the matter. The Company recorded these amounts in the second quarter of 2011.

BLM Settlement—On March 28, 2011, the Company entered into a settlement agreement with the Bureau of Land Management (BLM) resolving all claims by the BLM that the Company did not comply with BLM regulations relating to the operation and position of certain valves, and the submission of related site facility diagrams, in its Uinta operations. The settlement agreement confirmed that the Company promptly remediated the alleged noncompliance upon learning of it, and cooperated with the BLM's investigation, and that there is no evidence of any senior Company management knowledge of the alleged noncompliance, or of any environmental harm or loss of oil or royalty revenue resulting from such alleged noncompliance. The Company paid a $2.1 million civil penalty to the BLM under the settlement agreement in April 2011.

Royalty Payments—Certain of the Company's royalty payment calculations are being disputed. The Company believes that its royalty calculations are in accordance with applicable leases and other agreements. However, the disputed amounts that the Company may be required to pay are up to approximately $7 million.

Other—The Company is involved in various other lawsuits, claims and inquiries, most of which are routine to the nature of its business. In the opinion of management, the resolution of these matters will not have a material effect on its financial position, results of operations or operating cash flows.

Environmental Matters

The Company has no material accrued environmental liabilities for its sites, including sites in which governmental agencies have designated the Company as a potentially responsible party, because it is not probable that a loss will be incurred and the minimum cost and/or amount of loss cannot be reasonably estimated. However, due to of the uncertainties associated with environmental assessment and remediation activities, future expense to remediate the currently identified sites, and sites identified in the future, if any, could be incurred. Management believes, based upon current site assessments, that the ultimate resolution of any matters will not result in material costs incurred.

- Definition

The entire disclosure for commitments and contingencies.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Interpretation (FIN)
-Number 14
-Paragraph 3
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 5
-Paragraph 9, 10, 11, 12
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.25)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Publisher FASB
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-Topic 825
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-URI http://asc.fasb.org/extlink&oid=6449706&loc=d3e16207-108621

+ Details

Acquisitions (Tables)

6 Months Ended

Jun. 30, 2011

Acquisitions

Consideration paid to sellers and recognized amounts of identifiable assets acquired and liabilities assumed

The following table summarizes the consideration paid and the amounts of the assets acquired and liabilities assumed as of May 25, 2011:

		(in thousands)

Consideration paid to sellers:
Cash consideration		$	129,376

Recognized amounts of identifiable assets acquired and liabilities assumed:
	Proved developed and undeveloped properties		129,631
	Asset retirement obligation		(119	)
	Other liabilities assumed		(136	)

Total identifiable net assets		$	129,376

The following table summarizes the consideration paid to the sellers and the amounts of the assets acquired and liabilities assumed in the Permian Acquisitions:

		(in thousands)

Consideration paid to sellers:
Cash consideration		$	327,032

Recognized amounts of identifiable assets acquired and liabilities assumed:
	Proved developed and undeveloped properties		332,214
	Other assets acquired		342
	Asset retirement obligation		(3,498	)
	Deferred income tax liability		(647	)
	Other liabilities assumed		(333	)

Total identifiable net assets		$	328,078

- Definition

Tabular disclosure of a material business combination completed during the period, including background, timing, and recognized assets and liabilities. This table does not include leveraged buyouts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 141
-Paragraph 51
-Subparagraph a
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 141
-Paragraph 52
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 141R
-Paragraph 68
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 141R
-Appendix F
-Paragraph F4
-Subparagraph e

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
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-URI http://asc.fasb.org/extlink&oid=6972119&loc=d3e1486-128463

+ Details

Earnings (Loss) Per Share and Comprehensive (Loss) Earnings (Tables)

6 Months Ended

Jun. 30, 2011

Earnings Per Share and Comprehensive Earnings

Computation of basic and diliuted earnings (loss) per share

	Three Months Ended June 30,				Six Months Ended June 30,

(in thousands, except per share data)	2011		2010		2011		2010
Net earnings	$	105,166	$	89,023	$	52,669	$	106,692
Less: earnings allocable to participating securities		1,012		1,713		544		2,133

Earnings available for common shareholders	$	104,154	$	87,310	$	52,125	$	104,559
Basic earnings per share	$	1.93	$	1.65	$	0.97	$	2.01

Diluted earnings per share	$	1.90	$	1.64	$	0.95	$	2.00

Weighted average shares outstanding—basic		54,004		52,965		53,936		52,027
Add: Dilutive effects of stock options and RSUs		704		448		755		380

Weighted average shares outstanding—dilutive		54,708		53,413		54,691		52,407

Components of other comprehensive earnings (loss)

	Three months ended June 30,				Six months ended June 30,

(in thousands)	2011		2010		2011		2010
Net earnings	$	105,166	$	89,023	$	52,669	$	106,692
Amortization of Accumulated other comprehensive loss related to de-designated hedges, net of income tax benefits of $5,837, $2,478, $11,673, and $4,563, respectively		9,522		4,044		19,045		7,444

Comprehensive earnings	$	114,688	$	93,067	$	71,714	$	114,136

Asset Retirement Obligation (Tables)

6 Months Ended

Jun. 30, 2011

Asset Retirement Obligation

Summary of change in asset retirement obligation

	Six months ended June 30,

(in thousands)	2011			2010
Beginning balance at January 1	$	53,443		$	43,487
Liabilities incurred		1,642			1,860
Liabilities settled		(864	)		(1,534	)
Liabilities assumed		119			3,309
Accretion expense		2,545			2,191

Ending balance at June 30	$	56,885		$	49,313

Equity Incentive Compensation Plans (Tables)

6 Months Ended

Jun. 30, 2011

Equity Incentive Compensation Plans

Schedule of stock options or units activity

				Weighted Average Exercise Price		Aggregate Intrinsic Value (in thousands)(1)

Outstanding at January 1, 2011		2,017,225		$	25.87	$	35,974	1,884,937
	Granted	89,865			48.50
	Exercised	(229,685	)		14.93
	Cancelled/expired	—			—

Outstanding at June 30, 2011		1,877,405		$	28.29	$	46,637	1,656,002

(1): The intrinsic value of a stock option is the amount by which the market value of the underlying stock at the end of the related period exceeds the exercise price of the option.

Summary of assumptions to estimate fair value of stock options



Expected volatility	45.00	%
Risk-free interest rate	2.54	%
Dividend yield	0.62	%
Expected term (in years)	6.0

Summary of restricted stock units activity

				Weighted Average Grant Date Fair Value		Vest Date Fair Value (in thousands)

Outstanding at January 1, 2011		857,360		$	19.67
	Granted	153,240			47.78
	Issued	(14,515	)		38.69	$	678
	Canceled/expired	(3,388	)		25.47

Outstanding at June 30, 2011(1)(2)		992,697		$	23.70

(1): The balance outstanding includes 30,544 RSUs granted to the non-employee Directors that are 100% vested at date of grant but are subject to a deferral election before the corresponding shares are issued.
(2): The balance outstanding includes 294,767 RSUs granted to executive officers and other officers that have vested in accordance with the RSU agreement, but are subject to a deferral election before the corresponding shares are issued.

Summary of performance share awards activity

			Weighted Average Grant Date Fair Value		Vest Date Fair Value (in Thousands)

Outstanding at January 1, 2011		103,794	$	31.20
	Granted	65,620		51.86
	Issued	—		—	$	—
	Canceled/expired	—		—

Outstanding at June 30, 2011		169,414	$	39.20

Summary of assumptions used in valuing market-based restricted shares



Number of simulations	100,000
Expected volatility	44	%
Risk-free rate	1.15	%

Derivative Instruments (Tables)

6 Months Ended

Jun. 30, 2011

Derivative Instruments

Schedule of commodity derivatives



Oil Bbl/D:	20,020	19,000	13,000	2,000
Natural Gas MMBtu/D:	15,000	15,000	—	—

Schedule of crude oil three-way collars entered into during the period

Term		Floor/Swap/Ceiling Prices

February 2011 - December 2013	1,000	$70.00 / $90.00 / $116.50
Full year 2012 and 2013	1,000	$70.00 / $90.00 / $120.00
Full year 2012 and 2013	1,000	$70.00 / $95.00 / $120.10
June 2011 - December 2014	1,000	$77.95 / $105.00 / $115.00
Full year 2012, 2013, and 2014	1,000	$80.00 / $107.00 / $119.60

Schedule of derivative assets and liabilities

		June 30, 2011

		Derivative Assets			Derivative Liabilities
(in millions)		Balance Sheet Classification	Fair Value		Balance Sheet Classification	Fair Value
Current:
	Commodity	Derivative assets	$	3.1	Derivative liabilities	$	60.4
Long term:
	Commodity	Derivative assets		1.4	Derivative liabilities		46.5

Total derivatives			$	4.5		$	106.9

		December 31, 2010

		Derivative Assets			Derivative Liabilities
(in millions)		Balance Sheet Classification	Fair Value		Balance Sheet Classification	Fair Value
Current:
	Commodity	Derivative assets	$	2.7	Derivative liabilities	$	84.9
Long term:
	Commodity	Derivative assets		2.1	Derivative liabilities		33.5

Total derivatives			$	4.8		$	118.4

Summary of gains (losses) before income taxes of derivative instruments recognized in the condensed statements of income (loss)

		Three months ended June 30,						Six months ended June 30,

	Location of (Gain) Loss Recognized in Earnings	Three months ended June 30,						Six months ended June 30,
Description of (Gain) Loss	Location of (Gain) Loss Recognized in Earnings	2011			2010			2011		2010
Commodity
(Gain) loss reclassified from AOCL into earnings (amortization of frozen amounts)	Sales of oil and gas	$	14.9		$	4.1		$	29.5	$	6.9
(Gain) loss recognized in earnings (cash settlements and mark-to-market movements)	Realized and unrealized (gain) loss on derivatives, net		(91.8	)		(58.8	)		35.7		(63.7	)
Interest rate
(Gain) loss reclassified from AOCL into earnings (amortization of frozen amounts)	Interest	$	0.4		$	2.4		$	1.2	$	5.1
(Gain) loss recognized in earnings (cash settlements and mark-to-market movements)	Realized and unrealized (gain) loss on derivatives, net		—			2.7			—		6.0

- Definition

Tabular disclosure of the location and amount of gains and losses reported in the statement of financial performance, or when applicable, the statement of financial position. For example, (a) gains and losses recognized in the income statement on derivative instruments designated and qualifying as hedging instruments in fair value hedges and related hedged items designated and qualifying in fair value hedges and (b) gains and losses initially recognized in other comprehensive income on derivative instruments designated and qualifying as cash flow hedges.

+ References + Details

Fair Value Measurements (Tables)

6 Months Ended

Jun. 30, 2011

Fair Value Measurements

Assets and liabilities measured at fair value on a recurring basis

(in millions)		Total			Level 1		Level 2			Level 3

Commodity derivatives liability, net
	June 30, 2011	$	(102.4	)	$	—	$	(102.4	)	$	—
	December 31, 2010	$	(113.6	)	$	—	$	(11.8	)	$	(101.8	)

Changes in Level 3 fair value measurements

			Three months ended June 30,					Six months ended June 30,

(in millions)			2011		2010			2011			2010
Fair value liability, beginning of period			$	—	$	(34.5	)	$	(101.8	)	$	(26.0	)
	Transfers out of Level 3(1)			—		—			101.8			—
		Realized and unrealized gain included in earnings		—		41.2			—			41.9
	Settlements			—		(10.7	)		—			(19.9	)

Fair value liability, end of period			$	—	$	(4.0	)	$	—		$	(4.0	)

Total unrealized gain included in earnings related to financial assets and liabilities still on the Condensed Balance Sheet at June 30, 2011 and 2010			$	—	$	30.5		$	—		$	22.0

(1): During the first quarter of 2011, the inputs used to value oil collars, natural gas collars and natural gas basis swaps were directly or indirectly observable, and these instruments were transferred to level 2.

Schedule of fair values and carrying amounts of debt instruments

	June 30, 2011				December 31, 2010

(in millions)	Carrying Amount		Estimated Fair Value		Carrying Amount		Estimated Fair Value
Line of credit	$	13	$	13	$	5	$	5
Senior secured revolving credit facility		395		395		170		170
8.25% Senior subordinated notes due 2016		200		208		200		210
10.25% Senior notes due 2014		440		513		439		518
6.75% Senior notes due 2020		300		300		300		303

	$	1,348	$	1,429	$	1,114	$	1,206

- Definition

Tabular disclosure of the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments, assets, and liabilities. Such certain disclosures about the financial instruments, assets, and liabilities include: (1) the fair value of the required items together with their carrying amounts (as appropriate) and (2) the methodology and assumptions used in developing such estimates of fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 10
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 14
-Subparagraph a
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 15
-Subparagraph b-d
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 157
-Paragraph 32
-Subparagraph a, c(1), c(2), c(3), d
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 159
-Paragraph 18
-Subparagraph c(2), d, e, f
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 159
-Paragraph 19
-Subparagraph a, b, c(1), d(1)
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6947722&loc=d3e13433-108611

Reference 8: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6947722&loc=d3e13467-108611

Reference 9: http://www.xbrl.org/2003/role/presentationRef
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-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=6947722&loc=d3e13476-108611

Reference 10: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14172-108612

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19207-110258

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6447952&loc=d3e13220-108610

+ Details

- Definition

Tabular disclosure of the fair value measurement of liabilities using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances, separately presenting changes during the period attributable to the following: (1) total gains or losses for the period (realized and unrealized), segregating those gains or losses included in earnings (or changes in net assets), and gains or losses recognized in other comprehensive income and a description of where those gains or losses included in earnings (or changes in net assets) are reported in the statement of income (or activities); (2) purchases, sales, issuances, and settlements (each type disclosed separately); and (3) transfers in and transfers out of Level 3 (for example, transfers due to changes in the observability of significant inputs) by class of liability.

+ References + Details

Basis of Presentation (Details) - USD ($) $ in Millions	3 Months Ended
Basis of Presentation (Details) - USD ($) $ in Millions	Mar. 31, 2010	Jun. 30, 2011	Dec. 31, 2010
Prior period error adjustment and correction
Comprehensive (loss) earnings	$ 6.8
Outstanding checks in excess of the bank balance, included in accounts payable		$ 20.3	$ 16.3

- Definition

The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the reporting entity. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, but excludes any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 51
-Paragraph 8, 9, 10, 11, 12, 13, 14
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 51
-Paragraph 30
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 51
-Paragraph A5
-Appendix A

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6920043&loc=d3e557-108580

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Net Income
-URI http://asc.fasb.org/extlink&oid=6518256

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Other Comprehensive Income
-URI http://asc.fasb.org/extlink&oid=6519514

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6920043&loc=d3e540-108580

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Comprehensive Income
-URI http://asc.fasb.org/extlink&oid=6508144

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 51
-Paragraph 38
-Subparagraph c(3)
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Acquisitions (Details) $ in Thousands	1 Months Ended	3 Months Ended			6 Months Ended		12 Months Ended
Acquisitions (Details) $ in Thousands	May 31, 2011 USD ($) A	Jun. 30, 2011 USD ($) shares	Mar. 31, 2011 USD ($)	Jun. 30, 2010 USD ($)	Jun. 30, 2011 USD ($) shares	Jun. 30, 2010 USD ($)	Dec. 31, 2010 USD ($) shares	Nov. 30, 2010 USD ($)	Jan. 31, 2010 shares
Acquisitions
Purchase price paid, net of customary post-closing adjustments					$ 145,461	$ 150,674
Revenues generated by acquired properties		$ 230,760		$ 151,525	418,149	299,332
Operating costs - oil and gas production		58,780		$ 46,452	115,863	93,488
Recognized amounts of identifiable assets acquired and liabilities assumed:
Aggregate principal amount of senior notes due in november 2020 issued for financing acquisitions		$ 300,000			300,000		$ 300,000
Deferred income taxes					$ 19,572	$ 61,142
Class A
Recognized amounts of identifiable assets acquired and liabilities assumed:
Common stock shares issued for financing acquisitions (in shares) \| shares		51,604,476			51,604,476		51,426,232
Permian Basin Acquisitions
Consideration paid to seller:
Cash consideration							$ 327,032
Recognized amounts of identifiable assets acquired and liabilities assumed:
Proved developed and undeveloped properties							332,214
Other assets acquired							342
Asset retirement							(3,498)
Other liabilities assumed							(333)
Deferred income tax liability							(647)
Total identifiable net assets							$ 328,078
Number of separate acquisitions							3
Aggregate purchase price related to acquisitions							$ 327,000
Aggregate principal amount of senior notes due in november 2020 issued for financing acquisitions								$ 300,000
Interest rate of senior notes due in november 2020 (as a percent)								6.75%
Gain on purchase of oil and natural gas properties			$ 1,000
Deferred income taxes			$ 700
Permian Basin Acquisitions \| Class A
Recognized amounts of identifiable assets acquired and liabilities assumed:
Common stock shares issued for financing acquisitions (in shares) \| shares									8,000,000
Wolfberry Acquisition
Acquisitions
Interests acquired in producing properties (in net acres) \| A	6,000
Purchase price paid, net of customary post-closing adjustments	$ (129,400)
Initial purchase price	128,500
Customary post-closing adjustments	$ 900
Percentage of operation of acquired properties (as a percent)	97.00%
Percentage of average working interest (as a percent)	93.00%
Percentage Of net revenue interest (as a percent)	70.00%
Revenues generated by acquired properties		$ 1,400
Operating costs - oil and gas production		$ 300
Consideration paid to seller:
Cash consideration	$ 129,376
Recognized amounts of identifiable assets acquired and liabilities assumed:
Proved developed and undeveloped properties	129,631
Asset retirement	(119)
Other liabilities assumed	(136)
Total identifiable net assets	$ 129,376

Debt (Details) $ in Thousands	1 Months Ended	6 Months Ended
Debt (Details) $ in Thousands	Apr. 30, 2011	Jun. 30, 2011 USD ($)	Apr. 13, 2011 USD ($)	Dec. 31, 2010 USD ($)
Debt obligations
Short-term Bank Loans and Notes Payable		$ 12,700		$ 5,300
Total outstanding debt		395,000		170,000
Total outstanding under Line of Credit and Credit Agreement		408,000
Short Term Line of Credit
Debt obligations
Line of credit, current borrowing capacity		$ 40,000
Line of credit, maximum number of days which borrowings may be outstanding (in days)		30
Short-term Bank Loans and Notes Payable				$ 5,300
Reference rate for interest rate		LIBOR plus
Line of credit, margin rate over LIBOR (as a percent)		1.40%
Weighted average interest rate on outstanding borrowings (as a percent)		1.60%		1.70%
Senior secured revolving credit facility (Credit Agreement - long term)
Debt obligations
Reference rate for interest rate	LIBOR	LIBOR
Revolving credit facility maximum borrowing base before amendment			$ 875,000
Revolving credit facility maximum borrowing base after amendment			1,400,000
Lender commitments			$ 875,000
Annual commitment fee on the unused portion of the credit agreement low end of range (as a percent)	0.35%	0.35%
Annual commitment fee on the unused portion of the credit agreement high end of range (as a percent)	0.50%	0.50%
Total outstanding debt		$ 395,000		$ 170,000
Letters of credit that have been issued under the facility		23,000
Remaining borrowing capacity available under the agreement		$ 444,000
Debt instrument covenant consolidated interest coverage ratio numerator		2.75
Debt instrument covenant consolidated interest coverage ratio denominator		1.0
Debt instrument covenant consolidated minimum current ratio numerator		1.0
Debt instrument covenant consolidated minimum current ratio denominator		1.0
Senior secured revolving credit facility (Credit Agreement - long term) \| LIBOR
Debt obligations
Debt instrument basis spread on variable rate low end of range (as a percent)		1.50%	1.50%
Debt Instrument basis spread on variable Rate high end of range (as a percent)		2.50%	2.50%
Senior secured revolving credit facility (Credit Agreement - long term) \| Prime
Debt obligations
Debt instrument basis spread on variable rate low end of range (as a percent)		0.50%	0.50%
Debt Instrument basis spread on variable Rate high end of range (as a percent)		1.50%	1.50%
10.25% Senior notes due 2014
Debt obligations
Interest rate on debt instrument (as a percent)		10.25%		10.25%
8.25% Senior subordinated notes due 2016.
Debt obligations
Interest rate on debt instrument (as a percent)		8.25%		8.25%

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
Income Taxes (Details) - USD ($) $ in Millions	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
Income Taxes
Effective tax rate (as a percent)	38.60%	38.10%	37.00%	37.90%
Federal statutory rate (as a percent)			35.00%
Unrecognized tax benefit, if recognized, would affect the effective tax rate	$ 5.3		$ 5.3
Accrued interest recognized due to uncertain tax positions	0.9		0.9		$ 0.8
Maximum reduction in unrecognized tax benefits due to expiration of statutes of limitation and audit settlements in next 12 months	$ 1.9		$ 1.9

Earnings Per Share and Comprehensive Earnings (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Earnings per Share
Net earnings	$ 105,166	$ 89,023	$ 52,669	$ 106,692
Less: earnings allocable to participating securities	1,012	1,713	544	2,133
Earnings available for shareholders	$ 104,154	$ 87,310	$ 52,125	$ 104,559
Basic earnings per share (in dollars per share)	$ 1.93	$ 1.65	$ 0.97	$ 2.01
Diluted earnings per share (in dollars per share)	$ 1.90	$ 1.64	$ 0.95	$ 2.00
Weighted average shares outstanding - basic (in shares)	54,004	52,965	53,936	52,027
Add: Dilutive effects of stock options and RSUs (in shares)	704	448	755	380
Weighted average shares outstanding - dilutive (in shares)	54,708	53,413	54,691	52,407
Options not included in the diluted earnings per share calculation (in shares)		800		1,200
Comprehensive earnings
Net earnings	$ 105,166	$ 89,023	$ 52,669	$ 106,692
Amortization of Accumulated other comprehensive loss related to de-designated hedges, net of income tax benefits of $5,836, $2,478, $11,673, and $4,563, respectively	9,522	4,044	19,045	7,444
Amortization of Accumulated other comprehensive loss related to de-designated hedges income tax benefit	5,837	2,478	11,673	4,563
Total comprehensive earnings	$ 114,688	$ 93,067	$ 71,714	$ 114,136

Asset Retirement Obligation (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Change in the asset retirement obligation
Balance at the beginning of the period	$ 53,443	$ 43,487
Liabilities incurred	1,642	1,860
Liabilities settled	(864)	(1,534)
Liabilities assumed	119	3,309
Accretion expense	2,545	2,191
Balance at the end of the period	$ 56,885	$ 49,313

Equity Incentive Compensation Plans (Details) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Mar. 31, 2011 shares	Jun. 30, 2011 USD ($) $ / shares shares	Jun. 30, 2010 USD ($)	Jun. 30, 2011 USD ($) $ / shares shares	Jun. 30, 2010 USD ($)
Equity Incentive Compensation Plans
Total compensation cost \| $		$ 2,200	$ 1,800	$ 5,100	$ 4,100
Stock Options
Stock options activity
Outstanding at the beginning of the period (in shares)				2,017,225
Granted (in shares)				89,865
Exercised (in shares)				(229,685)
Outstanding at the end of the period (in shares)		1,877,405		1,877,405
Stock options, Weighted Average Exercise Price
Outstanding at the beginning of the period (in dollars per share) \| $ / shares				$ 25.87
Granted (in dollars per share) \| $ / shares		$ 48.50		48.50
Exercised (in dollars per share) \| $ / shares		14.93		14.93
Outstanding at the end of the period (in dollars per share) \| $ / shares		$ 28.29		$ 28.29
Stock options, Aggregate Intrinsic Value
Outstanding at the beginning of the period \| $				$ 35,974
Outstanding at the end of the period \| $		$ 46,637		$ 46,637
Stock options, Number of Shares Exercisable
Options outstanding at the beginning of the period (in shares)				1,884,937
Options outstanding at the end of the period (in shares)		1,656,002		1,656,002
Vesting period (in years)				four-year
Fair value assumptions
Total unrecognized compensation cost \| $		$ 1,700		$ 1,700
Period of recognition of unrecognized compensation cost (in years)				3.8
Stock Options \| Executive officers and other officers
Stock options activity
Granted (in shares)	89,865
Fair value assumptions
Expected volatility (as a percent)	45.00%
Risk-free interest rate (as a percent)	2.54%
Dividend yield (as a percent)	0.62%
Expected term (in years)	6.0

Equity Incentive Compensation Plans (Details 2) $ / shares in Units, $ in Thousands	1 Months Ended	6 Months Ended
	Mar. 31, 2011 shares	Jun. 30, 2011 USD ($) $ / shares shares
Restricted Stock Units
Other than stock options activity
Outstanding at the beginning of the period (in shares)		857,360
Granted (in shares)		152,240
Issued (in shares)		(14,515)
Canceled/expired (in shares)		(3,388)
Outstanding at the end of the period (in shares)		992,697
Weighted-average grant-date fair value
Outstanding at the beginning of the period (in dollars per share) \| $ / shares		$ 19.67
Granted (in dollars per share) \| $ / shares		47.78
Issued (in dollars per share) \| $ / shares		38.69
Canceled/expired (in dollars per share) \| $ / shares		25.47
Outstanding at the end of the period (in dollars per share) \| $ / shares		$ 23.70
Vest Date Fair Value
Issued \| $		$ 678
Total unrecognized compensation cost \| $		$ 10,500
Period of recognition of unrecognized compensation cost (in years)		3.8
Restricted Stock Units \| Executive officers and other officers
Vest Date Fair Value
Fully Vested Shares Outstanding Because Subject to Deferral Election by Executive Officers or Other Officers	65,620	294,767
Restricted Stock Units \| Non-employee directors
Vest Date Fair Value
Percentage of stock units vested at date of grant (as a percent)		100.00%
Fully Vested Shares Outstanding Because Subject to Non-Employee Director Deferral Election		30,544
Performance-Based RSUs
Other than stock options activity
Outstanding at the beginning of the period (in shares)		103,794
Granted (in shares)		65,620
Outstanding at the end of the period (in shares)		169,414
Weighted-average grant-date fair value
Outstanding at the beginning of the period (in dollars per share) \| $ / shares		$ 31.20
Granted (in dollars per share) \| $ / shares		51.86
Outstanding at the end of the period (in dollars per share) \| $ / shares		$ 39.20
Vest Date Fair Value
Total unrecognized compensation cost \| $		$ 2,300
Period of recognition of unrecognized compensation cost (in years)		2.5
Number of years of service to be completed to participate in the program (in years)	three-year
Minimum interest coverage ratio, numerator		2.5
Minimum interest coverage ratio, denominator		1.0
Number of weighted performance factors	2
Vesting period (in years)	three-year
Fair value assumptions used in market-based portion of performance shares valuation model (Monte Carlo model)
Number of simulations	100,000
Expected volatility (as a percent)	44.00%
Risk-free interest rate (as a percent)	1.15%

Derivative Instruments (Details) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
Derivative Instruments (Details) $ in Thousands	Jun. 30, 2011 USD ($) bbl MMBtu	Jun. 30, 2011 USD ($) bbl MMBtu	Jun. 30, 2012 USD ($)	Dec. 31, 2010 USD ($)
Discontinuance of cash flow hedge accounting
Unrealized losses, before tax due to a change in the fair value of open commodity and interest rate derivative contracts designated as cash flow hedges \| $	$ 39,900	$ 39,900		$ 70,700
Unrealized losses, after tax due to a change in the fair value of open commodity and interest rate derivative contracts designated as cash flow hedges \| $	(24,761)	(24,761)		$ (43,806)
Reclassified unrealized losses, before tax from AOCL into earnings \| $	15,300	30,700
Reclassified unrealized losses, after tax from AOCL into earnings \| $	$ 9,500	$ 19,045
Net losses after-tax expected to be reclassified into earnings from AOCL during the next twelve months \| $			$ 21,500
2011 \| Oil Bbl/D
Notional amount of derivative instruments
Notional amount of derivatives (Bbl/MMBtu)	20,020	20,020
2011 \| Natural Gas MMBtu/D
Notional amount of derivative instruments
Notional amount of derivatives (Bbl/MMBtu) \| MMBtu	15,000	15,000
2012 \| Oil Bbl/D
Notional amount of derivative instruments
Notional amount of derivatives (Bbl/MMBtu)	19,000	19,000
2012 \| Natural Gas MMBtu/D
Notional amount of derivative instruments
Notional amount of derivatives (Bbl/MMBtu) \| MMBtu	15,000	15,000
2013 \| Oil Bbl/D
Notional amount of derivative instruments
Notional amount of derivatives (Bbl/MMBtu)	13,000	13,000
2014 \| Oil Bbl/D
Notional amount of derivative instruments
Notional amount of derivatives (Bbl/MMBtu)	2,000	2,000
Full year 2012 and 2013 \| Oil Bbl/D \| Floor price $70 \| Ceiling price $120.00 \| Swap price $90.00
Notional amount of derivative instruments
Notional amount of derivatives (Bbl/MMBtu)	1,000	1,000
Full year 2012 and 2013 \| Oil Bbl/D \| Floor price $70 \| Ceiling price $120.10 \| Swap price $95.00
Notional amount of derivative instruments
Notional amount of derivatives (Bbl/MMBtu)	1,000	1,000
June 2011 - December 2014 \| Oil Bbl/D \| Floor price $77.95 \| Ceiling price $ 115.00 \| Swap price $ 105.00
Notional amount of derivative instruments
Notional amount of derivatives (Bbl/MMBtu)	1,000	1,000
Full year 2012, 2013, and 2014 \| Oil Bbl/D \| Floor price $80.00 \| Ceiling price $ 119.60 \| Swap price $ 107.00
Notional amount of derivative instruments
Notional amount of derivatives (Bbl/MMBtu)	1,000	1,000
Three-way collars \| February 2011 - December 2013 \| Oil Bbl/D \| Floor price $70 \| Ceiling price $116.50 \| Swap price $90.00
Notional amount of derivative instruments
Notional amount of derivatives (Bbl/MMBtu)	1,000	1,000

Derivative Instruments (Details 2) - USD ($) $ in Millions	Jun. 30, 2011	Dec. 31, 2010
Fair value derivative assets and liabilities classified in condensed balance sheets
Derivative Assets	$ 4.5	$ 4.8
Derivative Liabilities	106.9	118.4
Commodity contract \| Current assets
Fair value derivative assets and liabilities classified in condensed balance sheets
Derivative Assets	3.1	2.7
Commodity contract \| Long term assets
Fair value derivative assets and liabilities classified in condensed balance sheets
Derivative Assets	1.4	2.1
Commodity contract \| Current liability
Fair value derivative assets and liabilities classified in condensed balance sheets
Derivative Liabilities	60.4	84.9
Commodity contract \| Long term liabilities
Fair value derivative assets and liabilities classified in condensed balance sheets
Derivative Liabilities	$ 46.5	$ 33.5

- Definition

Fair values as of the balance sheet date of all assets resulting from contracts that meet the criteria of being accounted for as derivative instruments, net of the effects of master netting arrangements.

+ References + Details

- Definition

Fair values as of the balance sheet date of all liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments, net of the effects of master netting arrangements.

+ References + Details

Derivative Instruments (Details 3) $ in Thousands	3 Months Ended		6 Months Ended
Derivative Instruments (Details 3) $ in Thousands	Jun. 30, 2011 USD ($)	Jun. 30, 2010 USD ($)	Jun. 30, 2011 USD ($)	Jun. 30, 2010 USD ($)
Location and the amount of derivative instrument gains (losses) before income taxes recognized in the condensed statements of income
(Gain) loss recognized in earnings (cash settlements and mark-to-market movements)	$ (91,808)	$ (56,057)	$ 35,708	$ (57,661)
Credit risk
Maximum loss if all counterparties to its derivative contracts failed to perform	$ 4,500		$ 4,500
Number of counterparties to the Company's commodity derivative contracts			9
Number of counterparties with net liability position	7		7
Derivative instruments, net liability position	$ 107,000		$ 107,000
Derivative instruments, number of major counterparties			3
Derivative value held by major counterparties (as a percent)			59.00%
Sales of oil and gas \| Commodity contract
Location and the amount of derivative instrument gains (losses) before income taxes recognized in the condensed statements of income
(Gain) loss reclassified from AOCL into earnings (amortization of frozen amounts)	14,900	4,100	$ 29,500	6,900
Realized and unrealized gain (loss) on derivatives, net \| Commodity contract
Location and the amount of derivative instrument gains (losses) before income taxes recognized in the condensed statements of income
(Gain) loss recognized in earnings (cash settlements and mark-to-market movements)	(91,800)	(58,800)	35,700	(63,700)
Realized and unrealized gain (loss) on derivatives, net \| Interest rate contract
Location and the amount of derivative instrument gains (losses) before income taxes recognized in the condensed statements of income
(Gain) loss recognized in earnings (cash settlements and mark-to-market movements)		2,700		6,000
Interest \| Interest rate contract
Location and the amount of derivative instrument gains (losses) before income taxes recognized in the condensed statements of income
(Gain) loss reclassified from AOCL into earnings (amortization of frozen amounts)	$ 400	$ 2,400	$ 1,200	$ 5,100

Fair Value Measurements (Details) - Assets and liabilities measured on a recurring basis - Commodity contract - USD ($) $ in Millions	Jun. 30, 2011	Dec. 31, 2010
Estimated Fair Value
Assets and liabilities measured at fair value on a recurring basis
Commodity derivatives liability, net	$ (102.4)	$ (113.6)
Level 1
Assets and liabilities measured at fair value on a recurring basis
Commodity derivatives liability, net	0.0	0.0
Level 2
Assets and liabilities measured at fair value on a recurring basis
Commodity derivatives liability, net	$ (102.4)	(11.8)
Level 3
Assets and liabilities measured at fair value on a recurring basis
Commodity derivatives liability, net		$ (101.8)

Fair Value Measurements (Details 2) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Fair Value Measurements (Details 2) - USD ($) $ in Millions	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Changes in Level 3 fair value measurements
Fair value liability, beginning of period	$ (34.5)	$ (101.8)	$ (26.0)
Transfers out of Level 3		$ 101.8
Realized and unrealized gain included in earnings	41.2		41.9
Settlements	(10.7)		(19.9)
Fair value liability, end of period	(4.0)		(4.0)
Total unrealized (loss) gain included in earnings related to financial assets and liabilities still on the Condensed Balance Sheet at June 30, 2011 and 2010	$ 30.5		$ 22.0

Fair Value Measurements (Details 3) - USD ($) $ in Millions	Jun. 30, 2011	Dec. 31, 2010
8.25% Senior subordinated notes due 2016.
Fair value and carrying value of debt instruments
Interest rate on debt instrument (as a percent)	8.25%	8.25%
10.25% Senior notes due 2014
Fair value and carrying value of debt instruments
Interest rate on debt instrument (as a percent)	10.25%	10.25%
6.75% Senior notes due 2020
Fair value and carrying value of debt instruments
Interest rate on debt instrument (as a percent)	6.75%	6.75%
Carrying Amount
Fair value and carrying value of debt instruments
Debt instrument	$ 1,348	$ 1,114
Carrying Amount \| Short Term Line of Credit
Fair value and carrying value of debt instruments
Debt instrument	13	5
Carrying Amount \| Senior secured revolving credit facility (Credit Agreement - long term)
Fair value and carrying value of debt instruments
Debt instrument	395	170
Carrying Amount \| 8.25% Senior subordinated notes due 2016.
Fair value and carrying value of debt instruments
Debt instrument	200	200
Carrying Amount \| 10.25% Senior notes due 2014
Fair value and carrying value of debt instruments
Debt instrument	440	439
Carrying Amount \| 6.75% Senior notes due 2020
Fair value and carrying value of debt instruments
Debt instrument	300	300
Estimated Fair Value
Fair value and carrying value of debt instruments
Debt instrument	1,429	1,206
Estimated Fair Value \| Short Term Line of Credit
Fair value and carrying value of debt instruments
Debt instrument	13	5
Estimated Fair Value \| Senior secured revolving credit facility (Credit Agreement - long term)
Fair value and carrying value of debt instruments
Debt instrument	395	170
Estimated Fair Value \| 8.25% Senior subordinated notes due 2016.
Fair value and carrying value of debt instruments
Debt instrument	208	210
Estimated Fair Value \| 10.25% Senior notes due 2014
Fair value and carrying value of debt instruments
Debt instrument	513	518
Estimated Fair Value \| 6.75% Senior notes due 2020
Fair value and carrying value of debt instruments
Debt instrument	$ 300	$ 303

Dry hole, abandonment, impairment and exploration (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011 USD ($)	Jun. 30, 2010 USD ($)	Jun. 30, 2011 USD ($)	Jun. 30, 2010 USD ($)
Dry hole, abandonment, impairment and exploration
Dry hole, abandonment, impairment and exploration expense	$ 310	$ 266	$ 423	$ 1,636
Number of wells that encountered mechanical failure		1		1

Commitments and Contingencies (Details) $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended
Commitments and Contingencies (Details) $ in Millions	Jul. 31, 2009 USD ($)	Jun. 30, 2011 USD ($)	Jun. 30, 2010 USD ($)	Jun. 30, 2011 USD ($) bbl	Jun. 30, 2010 USD ($)
Uinta Crude Oil Sales Contract
Minimum volume of Uinta light crude oil required to be purchased under crude oil sales contract (in Bbl/D) \| bbl				5,000
Gross oil production from Uinta properties (in Bbl/D) \| bbl				3,500
E. Texas Gathering System
Cash proceeds from the E. Texas financing obligation	$ 18.4
Net book value of E. Texas property	$ 16.7
E. Texas gathering system expenses incurred		$ 1.4	$ 1.5	$ 3.1	$ 2.6

Commitments and Contingencies (Details 2) - USD ($)	1 Months Ended
Commitments and Contingencies (Details 2) - USD ($)	Jun. 30, 2011	Apr. 30, 2011	Jan. 31, 2011
Carry and Earning Agreement
Commitments
Amount of penalty waived for each well not spud			$ 200,000
Obligation to pay a third party in connection with the construction			4,500,000
Cumulative contingent expenditure			9,000,000
Contingent expenditure payable by third party			$ 4,500,000
Penalty payable as a percentage of difference between specified amount and actual expended (as a percent)			50.00%
Specified amount for penalty calculation			$ 12,000,000
Bureau of Land Management
Commitments
Civil penalty paid		$ 2,100,000
Royalty payment disputes
Commitments
Disputed amounts required to be paid	$ 7,000,000
Order of Violation from Colorado Oil and Gas Conservative Commission
Commitments
Litigation Settlement Expenses to be Incurred	100,000
Litigation Settlement Funding to Mutually Acceptable Public Project	$ 73,000

Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Jun. 30, 2011	Jul. 25, 2011
Entity Registrant Name	BERRY PETROLEUM CO
Entity Central Index Key	0000778438
Document Type	10-Q
Document Period End Date	Jun. 30, 2011
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Document Fiscal Year Focus	2011
Document Fiscal Period Focus	Q2
Class A
Entity Common Stock, Shares Outstanding		51,733,091
Class B
Entity Common Stock, Shares Outstanding		1,797,784