Stone Energy (SGY) 10-Q 6 Nov 13 2013 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2013	Nov. 05, 2013
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-13	'
Document Fiscal Year Focus	'2013	'
Document Fiscal Period Focus	'Q3	'
Trading Symbol	'SGY	'
Entity Registrant Name	'STONE ENERGY CORP	'
Entity Central Index Key	'0000904080	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	49,993,835

CONDENSED_CONSOLIDATED_BALANCE

CONDENSED CONSOLIDATED BALANCE SHEET (USD $)	Sep. 30, 2013		Jun. 30, 2013	Dec. 31, 2012		Sep. 30, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Current assets:	'		'	'		'	'
Cash and cash equivalents	$243,075		'	$279,526		$176,186	$38,451
Accounts receivable	189,565		'	167,288		'	'
Fair value of hedging contracts	14,423		'	39,655		'	'
Current income tax receivable	10,893		'	10,027		'	'
Deferred taxes	26,350	[1]	'	15,514	[1]	'	'
Inventory	3,843		'	4,207		'	'
Other current assets	1,439		'	3,626		'	'
Total current assets	489,588		'	519,843		'	'
Oil and gas properties, full cost method of accounting:	'		'	'		'	'
Proved	7,589,153		'	7,244,466		'	'
Less: accumulated depreciation, depletion and amortization	-5,762,937		'	-5,510,166		'	'
Net proved oil and gas properties	1,826,216		'	1,734,300		'	'
Unevaluated	576,395		'	447,795		'	'
Other property and equipment, net	23,965		'	22,115		'	'
Fair value of hedging contracts	5,114		'	9,199		'	'
Other assets, net	49,148		'	43,179		'	'
Total assets	2,970,426		'	2,776,431		'	'
Current liabilities:	'		'	'		'	'
Accounts payable to vendors	104,486		'	94,361		'	'
Undistributed oil and gas proceeds	42,913		'	23,414		'	'
Accrued interest	14,272		'	18,546		'	'
Fair value of hedging contracts	8,261		'	149		'	'
Asset retirement obligations	60,938		'	66,260		'	'
Other current liabilities	21,680		'	16,765		'	'
Total current liabilities	252,550		'	219,495		'	'
Long-term debt	923,745		'	914,126		'	'
Deferred taxes	387,033	[1]	'	310,830	[1]	'	'
Asset retirement obligations	407,712		'	422,042		'	'
Fair value of hedging contracts	360		'	1,530		'	'
Other long-term liabilities	26,463		'	36,275		'	'
Total liabilities	1,997,863		'	1,904,298		'	'
Commitments and contingencies	'		'	'		'	'
Stockholders' equity:	'		'	'		'	'
Common stock, $.01 par value; authorized 100,000,000 shares; issued 48,750,533 and 48,392,552 shares, respectively	488		'	484		'	'
Treasury stock (16,582 shares, at cost)	-860		'	-860		'	'
Additional paid-in capital	1,393,439		'	1,386,475		'	'
Accumulated deficit	-426,917		'	-542,799		'	'
Accumulated other comprehensive income	6,413		24,500	28,833		'	'
Total stockholders' equity	972,563		'	872,133		'	'
Total liabilities and stockholders' equity	$2,970,426		'	$2,776,431		'	'
[1]	Deferred income taxes have been allocated to the Guarantor Subsidiary where related oil and gas properties reside.

CONDENSED_CONSOLIDATED_BALANCE1

CONDENSED CONSOLIDATED BALANCE SHEET (Parenthetical) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Statement Of Financial Position [Abstract]	'	'
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	48,750,533	48,392,552
Treasury stock, shares	16,582	16,582

CONDENSED_CONSOLIDATED_STATEME

CONDENSED CONSOLIDATED STATEMENT OF OPERATIONS (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Operating revenue:	'	'	'	'
Oil production	$186,608	$180,806	$558,031	$564,745
Gas production	52,728	34,003	137,382	91,006
Natural gas liquids production	16,476	11,910	36,854	35,228
Other operational income	873	678	2,659	2,520
Derivative income, net	'	'	'	3,119
Total operating revenue	256,685	227,397	734,926	696,618
Operating expenses:	'	'	'	'
Lease operating expenses	53,986	60,995	157,547	157,030
Transportation, processing and gathering expenses	13,081	6,762	27,374	15,911
Production taxes	5,224	1,842	11,404	7,578
Depreciation, depletion and amortization	92,853	89,274	255,497	260,982
Accretion expense	8,431	8,405	25,012	24,926
Salaries, general and administrative expenses	14,201	13,673	43,351	40,521
Incentive compensation expense	4,566	67	8,047	3,907
Other operational expenses	237	82	382	195
Derivative expense, net	1,684	1,812	1,537	'
Total operating expenses	194,263	182,912	530,151	511,050
Income from operations	62,422	44,485	204,775	185,568
Other (income) expenses:	'	'	'	'
Interest expense	7,922	7,692	26,452	21,107
Interest income	-1,311	-117	-1,543	-227
Other income	-782	-443	-2,190	-1,229
Total other (income) expenses	5,829	7,132	22,719	19,651
Income before income taxes	56,593	37,353	182,056	165,917
Provision (benefit) for income taxes:	'	'	'	'
Current	-88	595	-10,827	1,164
Deferred	20,579	13,099	77,001	59,573
Total income taxes	20,491	13,694	66,174	60,737
Net income	$36,102	$23,659	$115,882	$105,180
Basic earnings per share	$0.72	$0.48	$2.32	$2.13
Diluted earnings per share	$0.72	$0.48	$2.32	$2.13
Average shares outstanding	48,732	48,342	48,680	48,300
Average shares outstanding assuming dilution	48,776	48,384	48,720	48,343

CONDENSED_CONSOLIDATED_STATEME1

CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Statement Of Income And Comprehensive Income [Abstract]	'	'	'	'
Net income	$36,102	$23,659	$115,882	$105,180
Other comprehensive income (loss), net of tax effect:	'	'	'	'
Derivatives	-18,384	-33,166	-22,164	7,971
Foreign currency items	267	'	-256	'
Comprehensive income (loss)	$17,985	($9,507)	$93,462	$113,151

CONDENSED_CONSOLIDATED_STATEME2

CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:	'	'
Net income	$115,882	$105,180
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation, depletion and amortization	255,497	260,982
Accretion expense	25,012	24,926
Deferred income tax provision	77,001	59,573
Settlement of asset retirement obligations	-61,178	-47,211
Non-cash stock compensation expense	7,583	6,800
Excess tax benefits	-156	-882
Non-cash derivative expense (income)	1,626	-584
Non-cash interest expense	12,384	9,068
Other non-cash expense	'	16
Change in current income taxes	-704	-3,240
Increase in accounts receivable	-22,277	-15,832
(Increase) decrease in other current assets	2,187	-2,456
Decrease in inventory	158	136
Increase in accounts payable	8,035	6,116
Increase (decrease) in other current liabilities	20,251	-24,301
Other	-1,791	-4,378
Net cash provided by (used in) operating activities	439,510	373,913
Cash flows from investing activities:	'	'
Investment in oil and gas properties	-472,304	-445,311
Proceeds from sale of oil and gas properties, net of expenses	6,300	403
Sale of fixed assets	'	134
Investment in fixed and other assets	-3,830	-3,998
Change in restricted funds	-2,394	'
Net cash used in investing activities	-472,228	-448,772
Cash flows from financing activities:	'	'
Proceeds from bank borrowings	'	25,000
Repayments of bank borrowings	'	-70,000
Proceeds from issuance of senior convertible notes	'	300,000
Deferred financing costs of senior convertible notes	'	-8,855
Proceeds from sold warrants	'	40,170
Payments for purchased call options	'	-70,830
Deferred financing costs	-11	'
Excess tax benefits	156	882
Net payments for share-based compensation	-3,733	-3,773
Net cash (used in) provided by financing activities	-3,588	212,594
Effect of exchange rate changes on cash	-145	'
Net change in cash and cash equivalents	-36,451	137,735
Cash and cash equivalents, beginning of period	279,526	38,451
Cash and cash equivalents, end of period	$243,075	$176,186

Interim_Financial_Statements

Interim Financial Statements	9 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]	'
Interim Financial Statements	'
	Note 1 – Interim Financial Statements
	The condensed consolidated financial statements of Stone Energy Corporation (“Stone”) and its subsidiaries as of September 30, 2013 and for the three and nine month periods ended September 30, 2013 and 2012 are unaudited and reflect all adjustments (consisting only of normal recurring adjustments), which are, in the opinion of management, necessary for a fair presentation of the financial position and operating results for the interim periods. The condensed consolidated balance sheet as of December 31, 2012 has been derived from the audited financial statements as of that date contained in our Annual Report on Form 10-K for the year ended December 31, 2012 (our “2012 Annual Report on Form 10-K”). The condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto, together with management’s discussion and analysis of financial condition and results of operations, contained in our 2012 Annual Report on Form 10-K. The results of operations for the three and nine month periods ended September 30, 2013 are not necessarily indicative of future financial results.

Earnings_Per_Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	Note 2 – Earnings Per Share
	The following table sets forth the calculation of basic and diluted weighted average shares outstanding and earnings per share for the indicated periods.
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
		(In thousands, except per share amounts)
	Income (numerator):
	Basic:
	Net income	$	36,102		$	23,659		$	115,882		$	105,180
	Net income attributable to participating securities		(924	)		(564	)		(2,728	)		(2,283	)
	Net income attributable to common stock—basic	$	35,178		$	23,095		$	113,154		$	102,897
	Diluted:
	Net income	$	36,102		$	23,659		$	115,882		$	105,180
	Net income attributable to participating securities		(923	)		(563	)		(2,726	)		(2,281	)
	Net income attributable to common stock—diluted	$	35,179		$	23,096		$	113,156		$	102,899
	Weighted average shares (denominator):
	Weighted average shares—basic		48,732			48,342			48,680			48,300
	Dilutive effect of stock options		44			42			40			43
	Weighted average shares—diluted		48,776			48,384			48,720			48,343
	Basic earnings per share	$	0.72		$	0.48		$	2.32		$	2.13
	Diluted earnings per share	$	0.72		$	0.48		$	2.32		$	2.13
	Stock options that were considered antidilutive because the exercise price of the options exceeded the average price of our common stock for the applicable period totaled approximately 327,000 and 369,000 shares during the three and nine month periods ended September 30, 2013 and 2012, respectively.
	During the three months ended September 30, 2013 and 2012, respectively, approximately 22,000 and 59,000 shares of our common stock were issued from authorized shares upon the vesting (lapse of forfeiture restrictions) of restricted stock by employees and nonemployee directors. During the nine months ended September 30, 2013 and 2012, respectively, approximately 358,000 and 314,000 shares of our common stock were issued from authorized shares upon the vesting (lapse of forfeiture restrictions) of restricted stock by employees and nonemployee directors.
	Because it is management’s stated intention to redeem the principal amount of our 1 3⁄4% Senior Convertible Notes due 2017 (the “2017 Convertible Notes”) (see Note 4 – Long-Term Debt) in cash, we have used the treasury method for determining potential dilution in the diluted earnings per share computation. Since the average price of our common stock was less than the effective conversion price for such notes during the reporting period, the 2017 Convertible Notes were not dilutive for such period. Additionally, since the average price of our common stock was less than the strike price of the Sold Warrants (as defined in Note 4 – Long-Term Debt) for the reporting period, such warrants were also not dilutive for such period.

Derivative_Instruments_and_Hed

Derivative Instruments and Hedging Activities	9 Months Ended
	Sep. 30, 2013
Derivative Instruments And Hedging Activities Disclosure [Abstract]	'
Derivative Instruments and Hedging Activities	'
	Note 3 – Derivative Instruments and Hedging Activities
	Our hedging strategy is designed to protect our near and intermediate term cash flows from future declines in oil and natural gas prices. This protection is essential to capital budget planning, which is sensitive to expenditures that must be committed to in advance, such as rig contracts and the purchase of tubular goods. We enter into hedging transactions to secure a commodity price for a portion of future production that is acceptable at the time of the transaction. These hedges are designated as cash flow hedges upon entering into the contract. We do not enter into hedging transactions for trading purposes. We have no fair value hedges.
	The nature of a derivative instrument must be evaluated to determine if it qualifies for hedge accounting treatment. If the instrument qualifies for hedge accounting treatment, it is recorded as either an asset or liability measured at fair value and subsequent changes in the derivative’s fair value are recognized in stockholders’ equity through other comprehensive income (loss), net of related taxes, to the extent the hedge is considered effective. Additionally, monthly settlements of effective hedges are reflected in revenue from oil and gas production and cash flows from operations. Instruments not qualifying for hedge accounting treatment are recorded in our balance sheet at fair value, and changes in fair value are recognized in earnings through derivative expense (income). Monthly settlements of ineffective hedges are recognized in earnings through derivative expense (income) and cash flows from operations. Typically, a small portion of our derivative contracts are determined to be ineffective. This is because oil and natural gas price changes in the markets in which we sell our products are not 100% correlative to changes in the underlying price basis indicative in the derivative contract.
	We have entered into fixed-price swaps with various counterparties for a portion of our expected 2013, 2014 and 2015 oil and natural gas production from the Gulf Coast Basin. Some of our fixed-price oil swap settlements are based on an average of the New York Mercantile Exchange (“NYMEX”) closing price for West Texas Intermediate crude oil during the entire calendar month, and some are based on the average of the Intercontinental Exchange closing price for Brent crude oil during the entire calendar month. Our fixed-price gas swap settlements are based on the NYMEX price for the last day of a respective contract month. Swaps typically provide for monthly payments by us if prices rise above the swap price or to us if prices fall below the swap price. Our fixed-price swap contracts are with The Toronto-Dominion Bank, Barclays Bank PLC, BNP Paribas, The Bank of Nova Scotia, Bank of America, Natixis and Regions Bank.
	All of our derivative instruments at September 30, 2013 and December 31, 2012 were designated as effective cash flow hedges. However, during the three and nine month periods ended September 30, 2013 and 2012, certain of our derivative contracts were determined to be partially ineffective. The following tables disclose the location and fair value amounts of derivative instruments reported in our balance sheet at September 30, 2013 and December 31, 2012.
	Fair Value of Derivative Instruments at September 30, 2013
	(In millions)
			Asset Derivatives						Liability Derivatives
	Description		Balance Sheet Location		Fair				Balance Sheet Location	Fair
					Value					Value
	Commodity contracts		Current assets: Fair value of hedging contracts		$	14.4			Current liabilities: Fair value of hedging contracts	($	8.3	)
			Long-term assets: Fair value of hedging contracts			5.1			Long-term liabilities: Fair value of hedging contracts		(0.3	)
					$	19.5				($	8.6	)
	Fair Value of Derivative Instruments at December 31, 2012
	(In millions)
			Asset Derivatives						Liability Derivatives
	Description		Balance Sheet Location		Fair				Balance Sheet Location	Fair
					Value					Value
	Commodity contracts		Current assets: Fair value of hedging contracts		$	39.7			Current liabilities: Fair value of hedging contracts	($	0.1	)
			Long-term assets: Fair value of hedging contracts			9.2			Long-term liabilities: Fair value of hedging contracts		(1.5	)
					$	48.9				($	1.6	)
	The following tables disclose the effect of derivative instruments on the statement of operations for the three and nine month periods ended September 30, 2013 and 2012.
	Effect of Derivative Instruments on the Statement of Operations for the Three Months Ended September 30, 2013 and 2012
	(In millions)
	Derivatives in Cash		Amount of Gain							Gain (Loss) Reclassified from								Gain (Loss) Recognized in Income
	Flow Hedging		(Loss) Recognized							Accumulated Other Comprehensive Income								on Derivatives
	Relationships		in Other							into Income								(Ineffective Portion)
			Comprehensive							(Effective Portion) (a)
			Income on
			Derivatives
			2013				2012			Location		2013				2012		Location	2013			2012
	Commodity contracts		($	30.8	)		($	41.8	)	Operating revenue—		($	2.1	)		$	10	Derivative expense, net	($	1.7	)	($	1.8	)
										oil/gas production
	Total		($	30.8	)		($	41.8	)			($	2.1	)		$	10		($	1.7	)	($	1.8	)
	(a)	For the three months ended September 30, 2013, effective hedging contracts decreased oil revenue by $7.5 million and increased gas revenue by $5.4 million. For the three months ended September 30, 2012, effective hedging contracts increased oil revenue by $4.1 million and increased gas revenue by $5.9 million.
	Effect of Derivative Instruments on the Statement of Operations for the Nine Months Ended September 30, 2013 and 2012
	(In millions)
	Derivatives in Cash		Amount of Gain							Gain (Loss) Reclassified from								Gain (Loss) Recognized in Income
	Flow Hedging		(Loss) Recognized							Accumulated Other Comprehensive Income								on Derivatives
	Relationships		in Other							into Income								(Ineffective Portion)
			Comprehensive							(Effective Portion) (a)
			Income on
			Derivatives
			2013				2012			Location		2013				2012		Location	2013			2012
	Commodity contracts		($	20.9	)		$	30.8		Operating revenue—		$	13.8			$	18.4	Derivative (expense)	($	1.5	)	$	3.1
										oil/gas production								income, net
	Total		($	20.9	)		$	30.8				$	13.8			$	18.4		($	1.5	)	$	3.1
	(a)	For the nine months ended September 30, 2013, effective hedging contracts increased oil revenue by $2.4 million and increased gas revenue by $11.4 million. For the nine months ended September 30, 2012, effective hedging contracts increased oil revenue by $1.1 million and increased gas revenue by $17.3 million.
	At September 30, 2013, we had accumulated other comprehensive income of $6.6 million, net of tax, related to the fair value of our swap contracts that were outstanding as of September 30, 2013. We believe that approximately $3.8 million, net of tax, of the accumulated other comprehensive income will be reclassified into earnings in the next 12 months.
	Our derivative contracts are subject to netting arrangements. It is our policy not to offset our derivative contracts in presenting the fair value of these contracts as assets and liabilities in our balance sheet. The following presents the potential impact of the rights of offset associated with our recognized assets and liabilities at September 30, 2013:
			As Presented				Effects of			With Effects
			Without				Netting			of Netting
			Netting
			(In millions)
	Current assets: Fair value of hedging contracts		$	14.4			($	5	)	$	9.4
	Long-term assets: Fair value of hedging contracts			5.1				(3.5	)		1.6
	Current liabilities: Fair value of hedging contracts			(8.3	)			8.2			(0.1	)
	Long-term liabilities: Fair value of hedging contracts			(0.3	)			0.3			—
	The following table illustrates our hedging positions for calendar years 2013, 2014 and 2015 as of November 5, 2013:
			Fixed-Price Swaps
			NYMEX (except where noted)
			Natural Gas							Oil
			Daily Volume				Swap			Daily Volume				Swap
(MMBtus/d)			Price ($)				(Bbls/d)			Price ($)
2013			10,000				4			2,000	(a)			92.35
2013			10,000	(b)			4.05			1,000				92.8
2013			20,000	(a)			4.45			2,000	(c)			94.05
2013			10,000				5.27			1,000				94.45
2013			10,000				5.32			1,000				94.6
2013										1,000				97.15
2013										1,000				101.53
2013										1,000				103
2013										1,000				103.15
2013										1,000				104.25
2013										1,000				104.47
2013										1,000				104.5
2013										1,000	(d)			107.3
2014			10,000				4			1,000				90.06
2014			10,000				4.04			1,000				92.25
2014			10,000				4.105			1,000				93.55
2014			10,000				4.19			1,000				94
2014			10,000				4.25			1,000				98
2014			10,000				4.35			1,000				98.3
2014										2,000	(c)			98.85
2014										1,000				99.65
2014										1,000	(d)			103.3
2015			10,000				4.005			1,000				90
2015			10,000				4.22
2015			10,000				4.255
(a)	July through December
(b)	April through December
(c)	January through June
(d)	Brent crude oil contract

LongTerm_Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Long-Term Debt	'
	Note 4 – Long-Term Debt
	Long-term debt consisted of the following at:
		September 30,		December 31,
		2013		2012
		(In millions)
	8 5⁄8% Senior Notes due 2017	$	375	$	375
	1 3⁄4% Senior Convertible Notes due 2017		248.7		239.1
	7 1⁄2% Senior Notes due 2022		300		300
	Bank debt		—		—
	Total long-term debt	$	923.7	$	914.1
	Bank Debt
	On April 26, 2011, we entered into an amended and restated revolving credit facility with commitments totaling $700 million (subject to borrowing base limitations) through a syndicated bank group, replacing our previous facility. Our bank credit facility matures on April 26, 2015. On April 30, 2013, the bank group reaffirmed our existing borrowing base at $400 million. As of September 30 and November 5, 2013, we had no outstanding borrowings under our bank credit facility and letters of credit totaling $21.5 million had been issued pursuant to the facility, leaving $378.5 million of availability under our bank credit facility.
	During the three and nine month periods ended September 30, 2013, we recognized $0.5 million and $1.4 million, respectively, of interest expense related to fees on unused commitments under our bank credit facility. During the three and nine month periods ended September 30, 2013, we recognized $0.1 million and $0.4 million, respectively, of interest expense related to fees on our outstanding letters of credit.
	The borrowing base under our bank credit facility is redetermined semi-annually, in May and November, by the lenders taking into consideration the estimated value of our oil and gas properties and those of our direct and indirect material subsidiaries in accordance with the lenders’ customary practices for oil and gas loans. In addition, we and the lenders each have discretion at any time, but not more than two additional times in any calendar year, to have the borrowing base redetermined. Our bank credit facility is guaranteed by our only material subsidiary, Stone Energy Offshore, L.L.C. (“Stone Offshore”). Our bank credit facility is collateralized by substantially all of Stone’s and Stone Offshore’s assets. Stone and Stone Offshore are required to mortgage, and grant a security interest in, their oil and gas reserves representing at least 80% of the discounted present value of the future net cash flows from their oil and gas reserves reviewed in determining the borrowing base. At Stone’s option, loans under our bank credit facility will bear interest at a rate based on the adjusted London Interbank Offering (“Libor”) Rate plus an applicable margin, or a rate based on the prime rate or federal funds rate plus an applicable margin. Our bank credit facility provides for optional and mandatory prepayments, affirmative and negative covenants and interest coverage ratio and leverage ratio maintenance covenants. We were in compliance with all covenants as of September 30, 2013.
	2017 Convertible Notes
	On March 6, 2012, we issued in a private offering $300 million in aggregate principal amount of the 2017 Convertible Notes to qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”). The 2017 Convertible Notes are convertible into cash, shares of our common stock or a combination of cash and shares of our common stock, at our election, based on an initial conversion rate of 23.4449 shares of our common stock per $1,000 principal amount of 2017 Convertible Notes, which corresponds to an initial conversion price of approximately $42.65 per share of our common stock. On September 30, 2013, our closing share price was $32.43. The conversion rate, and thus the conversion price, may be adjusted under certain circumstances as described in the indenture related to the 2017 Convertible Notes. Upon conversion, we will be obligated to pay or deliver, as the case may be, cash, shares of our common stock or a combination of cash and shares of our common stock, at our election. Prior to December 1, 2016, the 2017 Convertible Notes will be convertible only upon the occurrence of certain events and during certain periods, and thereafter, at any time until the second scheduled trading day immediately preceding the maturity date.
	In connection with the offering, we entered into convertible note hedge transactions with respect to our common stock (the “Purchased Call Options”) with Barclays Capital Inc., acting as agent for Barclays Bank PLC and Bank of America, N.A. (the “Dealers”). We paid an aggregate amount of approximately $70.8 million to the Dealers for the Purchased Call Options. The Purchased Call Options cover, subject to customary antidilution adjustments, approximately 7,033,470 shares of our common stock at a strike price that corresponds to the initial conversion price of the 2017 Convertible Notes, also subject to adjustment, and are exercisable upon conversion of the 2017 Convertible Notes.
	We also entered into separate warrant transactions whereby, in reliance upon the exemption from registration provided by Section 4(2) of the Securities Act, we sold to the Dealers warrants to acquire, subject to customary antidilution adjustments, approximately 7,033,470 shares of our common stock (the “Sold Warrants”) at a strike price of $55.91 per share of our common stock. We received aggregate proceeds of approximately $40.1 million from the sale of the Sold Warrants to the Dealers. If, upon expiration of the Sold Warrants, the price per share of our common stock, as measured under the Sold Warrants, is greater than the strike price of the Sold Warrants, we will be required to issue, without further consideration, under each Sold Warrant a number of shares of our common stock with a value equal to the amount of such difference.
	As of September 30, 2013, the carrying amount of the liability component of the 2017 Convertible Notes was $248.7 million. During the three and nine month periods ended September 30, 2013, we recognized $3.3 million and $9.6 million, respectively, of interest expense for the amortization of the discount and $0.3 million and $0.9 million, respectively, of interest expense for the amortization of deferred financing costs related to the 2017 Convertible Notes. During the three and nine month periods ended September 30, 2013, we recognized $1.3 million and $3.9 million, respectively, of interest expense related to the contractual interest coupon on the 2017 Convertible Notes.
	2017 Notes
	During the three and nine month periods ended September 30, 2013, we recognized $0.4 million and $1.2 million, respectively, of interest expense for the amortization of deferred financing costs related to the 8 5⁄8% Senior Notes due 2017 (the “2017 Notes”). During the three and nine month periods ended September 30, 2013, we recognized $8.1 million and $24.3 million, respectively, of interest expense related to the contractual interest coupon on the 2017 Notes.
	2022 Notes
	During the three and nine month periods ended September 30, 2013, we recognized $0.2 million and $0.5 million, respectively, of interest expense for the amortization of deferred financing costs related to the 7 1⁄2% Senior Notes due 2022 (the “2022 Notes”). During the three and nine month periods ended September 30, 2013, we recognized $5.6 million and $16.8 million, respectively, of interest expense related to the contractual interest coupon on the 2022 Notes.

Asset_Retirement_Obligations

Asset Retirement Obligations	9 Months Ended
	Sep. 30, 2013
Asset Retirement Obligation Disclosure [Abstract]	'
Asset Retirement Obligations	'
	Note 5 – Asset Retirement Obligations
	The change in our asset retirement obligations during the nine months ended September 30, 2013 is set forth below:
		Nine Months
		Ended
		September 30,
		2013
		(In millions)
	Asset retirement obligations as of the beginning of the period, including current portion	$	488.3
	Liabilities incurred		16.5
	Liabilities settled		(61.2	)
	Accretion expense		25
	Asset retirement obligations as of the end of the period, including current portion	$	468.6

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2013
Business Combinations [Abstract]	'
Acquisitions	'
	Note 6 – Acquisitions
	In December 2012, we closed on the acquisition of an office building. The acquisition was accounted for according to the guidance provided in Accounting Standards Codification (“ASC”) 805, Business Combinations, which requires application of the acquisition method. This methodology requires us to record net assets acquired and consideration transferred at fair value. Differences between the net fair value of assets acquired and consideration transferred are recorded as goodwill or a bargain purchase gain. The building and land were recorded at fair value of $8.5 million. Consideration transferred in the transaction was $8.5 million in cash, with no goodwill or bargain purchase gain recorded.
	On June 18, 2012, we completed the acquisition of a 25% working interest in the five block deep water Pompano field in Mississippi Canyon, an approximate 14% working interest in Mississippi Canyon Block 29 and a 10% working interest in certain aliquots of Mississippi Canyon Block 72. The acquisition was accounted for according to the guidance provided in ASC 805, Business Combinations. Consideration transferred in the transaction was $26.4 million in cash, with no goodwill or bargain purchase gain recorded. The following represents the allocation of the recorded value of net assets acquired in the transaction.
		(In millions)
	Proved oil and gas properties	$	39.2
	Unevaluated oil and gas properties		1.6
	Asset retirement obligations		(14.4	)
	Total fair value of net assets	$	26.4

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Note 7 – Fair Value Measurements
	U.S. Generally Accepted Accounting Principles establish a fair value hierarchy that has three levels based on the reliability of the inputs used to determine the fair value. These levels include: Level 1, defined as inputs such 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.
	As of September 30, 2013 and December 31, 2012, we held certain financial assets and liabilities that are required to be measured at fair value on a recurring basis, including our commodity derivative instruments and our investments in marketable securities. We utilize the services of an independent third party to assist us in valuing our derivative instruments. We used the income approach in determining the fair value of our derivative instruments utilizing a proprietary pricing model. The model accounts for our credit risk and the credit risk of our counterparties in the discount rate applied to estimated future cash inflows and outflows. Our swap contracts are included within the Level 2 fair value hierarchy. For a more detailed description of our derivative instruments, see Note 3 – Derivative Instruments and Hedging Activities. We used the market approach in determining the fair value of our investments in marketable securities, which are included within the Level 1 fair value hierarchy.
	The following tables present our assets and liabilities that are measured at fair value on a recurring basis at September 30, 2013:
		Fair Value Measurements at September 30, 2013
	Assets	Total			Quoted Prices		Significant			Significant
					in Active		Other			Unobservable
					Markets for		Observable			Inputs
					Identical Assets		Inputs			(Level 3)
					(Level 1)		(Level 2)
		(In millions)
	Marketable securities	$	8		$	8	$	—		$	—
	Hedging contracts		19.5			—		19.5			—
	Total	$	27.5		$	8	$	19.5		$	—
		Fair Value Measurements at September 30, 2013
	Liabilities	Total			Quoted Prices		Significant			Significant
					in Active		Other			Unobservable
					Markets for		Observable			Inputs
					Identical		Inputs			(Level 3)
					Liabilities		(Level 2)
					(Level 1)
		(In millions)
	Hedging contracts	($	8.6	)	$	—	($	8.6	)	$	—
	Total	($	8.6	)	$	—	($	8.6	)	$	—
	The following tables present our assets and liabilities that are measured at fair value on a recurring basis at December 31, 2012:
		Fair Value Measurements at December 31, 2012
	Assets	Total			Quoted Prices		Significant			Significant
					in Active		Other			Unobservable
					Markets for		Observable			Inputs
					Identical Assets		Inputs			(Level 3)
					(Level 1)		(Level 2)
		(In millions)
	Marketable securities	$	13.5		$	13.5	$	—		$	—
	Hedging contracts		48.9			—		48.9			—
	Total	$	62.4		$	13.5	$	48.9		$	—
		Fair Value Measurements at December 31, 2012
	Liabilities	Total			Quoted Prices		Significant			Significant
					in Active		Other			Unobservable
					Markets for		Observable			Inputs
					Identical		Inputs			(Level 3)
					Liabilities		(Level 2)
					(Level 1)
		(In millions)
	Hedging contracts	($	1.6	)	$	—	($	1.6	)	$	—
	Total	($	1.6	)	$	—	($	1.6	)	$	—
	The fair value of cash and cash equivalents and our variable-rate bank debt approximated book value at September 30, 2013 and December 31, 2012. As of September 30, 2013 and December 31, 2012, the fair value of the 2017 Notes was approximately $397.5 million and $401.3 million, respectively. As of September 30, 2013 and December 31, 2012, the fair value of the liability component of the 2017 Convertible Notes was approximately $287.4 million and $249.6 million, respectively. As of September 30, 2013 and December 31, 2012, the fair value of the 2022 Notes was approximately $317.3 million and $314.3 million, respectively.
	The fair value of the 2017 Notes and the fair value of the 2022 Notes were determined based upon quotes obtained from brokers, which represent Level 1 inputs. We applied fair value concepts in determining the liability component of the 2017 Convertible Notes (see Note 4 – Long-Term Debt) at inception, September 30, 2013 and December 31, 2012. The fair value of the liability was estimated using an income approach. The significant inputs in these determinations were market interest rates based on quotes obtained from brokers and represent Level 2 inputs.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Loss)	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Accumulated Other Comprehensive Income (Loss)	'
	Note 8 – Accumulated Other Comprehensive Income (Loss)
	Changes in accumulated other comprehensive income (loss) by component for the three and nine month periods ended September 30, 2013 were as follows (in millions):
		Cash Flow			Foreign			Total
		Hedges			Currency
					Items
	For the Three Months Ended September 30, 2013
	Beginning balance, net of tax	$	25		($	0.5	)	$	24.5
	Other comprehensive income (loss) before reclassifications:
	Change in fair value of derivatives		(30.8	)		—			(30.8	)
	Foreign currency translations		—			0.3			0.3
	Income tax effect		11.1			—			11.1
	Net of tax		(19.7	)		0.3			(19.4	)
	Amounts reclassified from accumulated other comprehensive income:
	Operating revenue: oil/gas production		2.1			—			2.1
	Income tax effect		(0.8	)		—			(0.8	)
	Net of tax		1.3			—			1.3
	Other comprehensive income (loss), net of tax		(18.4	)		0.3			(18.1	)
	Ending balance, net of tax	$	6.6		($	0.2	)	$	6.4
	For the Nine Months Ended September 30, 2013
	Beginning balance, net of tax	$	28.8		$	—		$	28.8
	Other comprehensive income (loss) before reclassifications:
	Change in fair value of derivatives		(20.9	)		—			(20.9	)
	Foreign currency translations		—			(0.2	)		(0.2	)
	Income tax effect		7.6			—			7.6
	Net of tax		(13.3	)		(0.2	)		(13.5	)
	Amounts reclassified from accumulated other comprehensive income:
	Operating revenue: oil/gas production		(13.8	)		—			(13.8	)
	Income tax effect		4.9			—			4.9
	Net of tax		(8.9	)		—			(8.9	)
	Other comprehensive income (loss), net of tax		(22.2	)		(0.2	)		(22.4	)
	Ending balance, net of tax	$	6.6		($	0.2	)	$	6.4
	In 2012, the only component of accumulated other comprehensive income (loss) related to our cash flow hedges. Changes in accumulated other comprehensive income (loss) for the three and nine month periods ended September 30, 2012 were as follows (in millions):
		Cash Flow
		Hedges
	For the Three Months Ended September 30, 2012
	Beginning balance, net of tax	$	63
	Other comprehensive income (loss) before reclassifications:
	Change in fair value of derivatives		(41.8	)
	Income tax effect		15
	Net of tax		(26.8	)
	Amounts reclassified from accumulated other comprehensive income:
	Operating revenue: oil/gas production		(10.0	)
	Income tax effect		3.6
	Net of tax		(6.4	)
	Other comprehensive income, net of tax		(33.2	)
	Ending balance, net of tax	$	29.8
	For the Nine Months Ended September 30, 2012
	Beginning balance, net of tax	$	21.9
	Other comprehensive income (loss) before reclassifications:
	Change in fair value of derivatives		30.8
	Income tax effect		(11.1	)
	Net of tax		19.7
	Amounts reclassified from accumulated other comprehensive income:
	Operating revenue: oil/gas production		(18.4	)
	Income tax effect		6.6
	Net of tax		(11.8	)
	Other comprehensive income, net of tax		7.9
	Ending balance, net of tax	$	29.8

Investment_in_Oil_and_Gas_Prop

Investment in Oil and Gas Properties	9 Months Ended
	Sep. 30, 2013
Extractive Industries [Abstract]	'
Investment in Oil and Gas Properties	'
	Note 9 – Investment in Oil and Gas Properties
	In April 2013, we entered into an agreement to participate in the drilling of exploratory wells in Canada. Included in unevaluated oil and gas property costs at September 30, 2013 are $9.7 million of capital expenditures related to our oil and gas property investments in Canada.

Commitments_and_Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2013
Commitments And Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Note 10 – Commitments and Contingencies
	We are named as a defendant in certain lawsuits and are a party to certain regulatory proceedings arising in the ordinary course of business. We do not expect that these matters, individually or in the aggregate, will have a material adverse effect on our financial condition.
	Franchise Tax Action. We have been served with several petitions filed by the Louisiana Department of Revenue (the “LDR”) in Louisiana state court claiming additional franchise taxes due. In addition, we received preliminary assessments from the LDR for additional franchise taxes resulting from audits of Stone and other subsidiaries. These petitions and assessments all relate to the LDR’s assertion that sales of crude oil and natural gas from properties located on the Outer Continental Shelf (the “OCS”), which are transported through the State of Louisiana, should be sourced to the State of Louisiana for purposes of computing the Louisiana franchise tax apportionment ratio. We disagree with these contentions and are defending ourselves against these claims. Total asserted claims plus estimated accrued interest amount to approximately $30.5 million. The franchise tax years 2010, 2011 and 2012 for Stone remain subject to examination, which potentially exposes us to additional estimated assessments of $3.4 million including accrued interest. We estimate the potential range of loss upon resolution of this matter to be between $0 and $33.9 million.

Subsequent_Event

Subsequent Event	9 Months Ended
	Sep. 30, 2013
Subsequent Events [Abstract]	'
Subsequent Event	'
	Note 11 – Subsequent Event
	In October 2013, we completed the sale of our interest in the Weeks Island field for cash consideration of approximately $46 million. The sale will be accounted for as an adjustment to capitalized costs with no gain or loss recognized.

Guarantor_Financial_Statements

Guarantor Financial Statements	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Guarantor Financial Statements	'
	Note 12 – Guarantor Financial Statements
	Stone Offshore is an unconditional guarantor (the “Guarantor Subsidiary”) of the 2017 Convertible Notes, the 2017 Notes and the 2022 Notes. Our other subsidiaries (the “Non-Guarantor Subsidiaries”) have not provided guarantees. The following presents unaudited condensed consolidating financial information as of September 30, 2013 and December 31, 2012 and for the three and nine month periods ended September 30, 2013 and 2012 on an issuer (parent company), Guarantor Subsidiary, Non-Guarantor Subsidiaries and consolidated basis. Elimination entries presented are necessary to combine the entities.
	CONDENSED CONSOLIDATING BALANCE SHEET
	30-Sep-13
	(In thousands)
			Parent			Guarantor			Non-Guarantor			Eliminations			Consolidated
						Subsidiary			Subsidiaries
	Assets
	Current assets:
	Cash and cash equivalents		$	191,193		$	51,242		$	640		$	—		$	243,075
	Accounts receivable			83,310			313,610			—			(207,355	)		189,565
	Fair value of hedging contracts			—			14,423			—			—			14,423
	Current income tax receivable			10,893			—			—			—			10,893
	Deferred taxes *			6,631			19,719			—			—			26,350
	Inventory			3,560			283			—			—			3,843
	Other current assets			1,439			—			—			—			1,439
	Total current assets			297,026			399,277			640			(207,355	)		489,588
	Oil and gas properties, full cost method: Proved			1,211,964			6,377,189			—			—			7,589,153
	Less: accumulated DD&A			(429,380	)		(5,333,557	)		—			—			(5,762,937	)
	Net proved oil and gas properties			782,584			1,043,632			—			—			1,826,216
	Unevaluated			274,986			291,750			9,659			—			576,395
	Other property and equipment, net			23,965			—			—			—			23,965
	Fair value of hedging contracts			—			5,114			—			—			5,114
	Other assets, net			44,324			1,349			3,475			—			49,148
	Investment in subsidiary			896,798			—			13,116			(909,914	)		—
	Total assets		$	2,319,683		$	1,741,122		$	26,890		($	1,117,269	)	$	2,970,426
	Liabilities and Stockholders’ Equity
	Current liabilities:
	Accounts payable to vendors		$	289,204		$	22,576		$	61		($	207,355	)	$	104,486
	Undistributed oil and gas proceeds			39,141			3,772			—			—			42,913
	Accrued interest			14,272			—			—			—			14,272
	Fair value of hedging contracts			—			8,261			—			—			8,261
	Asset retirement obligations			—			60,938			—			—			60,938
	Other current liabilities			17,242			4,438			—			—			21,680
	Total current liabilities			359,859			99,985			61			(207,355	)		252,550
	Long-term debt			923,745			—			—			—			923,745
	Deferred taxes *			31,295			355,738			—			—			387,033
	Asset retirement obligations			5,758			401,954			—			—			407,712
	Fair value of hedging contracts			—			360			—			—			360
	Other long-term liabilities			26,463			—			—			—			26,463
	Total liabilities			1,347,120			858,037			61			(207,355	)		1,997,863
	Commitments and contingencies
	Stockholders’ equity:
	Common stock			488			—			—			—			488
	Treasury stock			(860	)		—			—			—			(860	)
	Additional paid-in capital			1,393,439			1,496,509			27,404			(1,523,913	)		1,393,439
	Accumulated deficit			(426,917	)		(620,093	)		(64	)		620,157			(426,917	)
	Accumulated other comprehensive income (loss)			6,413			6,669			(511	)		(6,158	)		6,413
	Total stockholders’ equity			972,563			883,085			26,829			(909,914	)		972,563
	Total liabilities and stockholders’ equity		$	2,319,683		$	1,741,122		$	26,890		($	1,117,269	)	$	2,970,426
	*	Deferred income taxes have been allocated to the Guarantor Subsidiary where related oil and gas properties reside.
	CONDENSED CONSOLIDATING BALANCE SHEET
	31-Dec-12
	(In thousands)
			Parent			Guarantor			Non-Guarantor			Eliminations			Consolidated
						Subsidiary			Subsidiaries
	Assets
	Current assets:
	Cash and cash equivalents		$	228,398		$	51,128		$	—		$	—		$	279,526
	Accounts receivable			59,213			108,075			—			—			167,288
	Fair value of hedging contracts			—			39,655			—			—			39,655
	Current income tax receivable			10,027			—			—			—			10,027
	Deferred taxes *			5,947			9,567			—			—			15,514
Inventory			3,924			283			—			—			4,207
Other current assets			3,626			—			—			—			3,626
Total current assets			311,135			208,708			—			—			519,843
Oil and gas properties, full cost method: Proved			1,004,808			6,239,658			—			—			7,244,466
Less: accumulated DD&A			(370,111	)		(5,140,055	)		—			—			(5,510,166	)
Net proved oil and gas properties			634,697			1,099,603			—			—			1,734,300
Unevaluated			254,757			193,038			—			—			447,795
Other property and equipment, net			22,115			—			—			—			22,115
Fair value of hedging contracts			—			9,199			—			—			9,199
Other assets, net			41,679			1,500			—			—			43,179
Investment in subsidiary			736,331			—			—			(736,331	)		—
Total assets		$	2,000,714		$	1,512,048		$	—		($	736,331	)	$	2,776,431
Liabilities and Stockholders’ Equity
Current liabilities:
Accounts payable to vendors		$	74,503		$	19,858		$	—		$	—		$	94,361
Undistributed oil and gas proceeds			21,841			1,573			—			—			23,414
Accrued interest			18,546			—			—			—			18,546
Fair value of hedging contracts			—			149			—			—			149
Asset retirement obligations			—			66,260			—			—			66,260
Other current liabilities			16,765			—			—			—			16,765
Total current liabilities			131,655			87,840			—			—			219,495
Long-term debt			914,126			—			—			—			914,126
Deferred taxes *			47,758			263,072			—			—			310,830
Asset retirement obligations			5,479			416,563			—			—			422,042
Fair value of hedging contracts			—			1,530			—			—			1,530
Other long-term liabilities			29,563			6,712			—			—			36,275
Total liabilities			1,128,581			775,717			—			—			1,904,298
Commitments and contingencies
Stockholders’ equity:
Common stock			484			—			—			—			484
Treasury stock			(860	)		—			—			—			(860	)
Additional paid-in capital			1,386,475			1,496,510			—			(1,496,510	)		1,386,475
Accumulated deficit			(542,799	)		(789,012	)		—			789,012			(542,799	)
Accumulated other comprehensive income			28,833			28,833			—			(28,833	)		28,833
Total stockholders’ equity			872,133			736,331			—			(736,331	)		872,133
Total liabilities and stockholders’ equity		$	2,000,714		$	1,512,048		$	—		($	736,331	)	$	2,776,431
*	Deferred income taxes have been allocated to the Guarantor Subsidiary where related oil and gas properties reside.
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS
THREE MONTHS ENDED SEPTEMBER 30, 2013
(In thousands)
		Parent			Guarantor			Non-			Eliminations			Consolidated
					Subsidiary			Guarantor
								Subsidiaries
Operating revenue:
Oil production		$	6,904		$	179,704		$	—		$	—		$	186,608
Gas production			19,971			32,757			—			—			52,728
Natural gas liquids production			9,224			7,252			—			—			16,476
Other operational income			711			162			—			—			873
Total operating revenue			36,810			219,875			—			—			256,685
Operating expenses:
Lease operating expenses			3,895			50,091			—			—			53,986
Transportation, processing and gathering expenses			10,072			3,009			—			—			13,081
Production taxes			1,773			3,451			—			—			5,224
Depreciation, depletion, amortization			26,728			66,125			—			—			92,853
Accretion expense			93			8,338			—			—			8,431
Salaries, general and administrative			14,202			—			(1	)		—			14,201
Incentive compensation expense			4,566			—			—			—			4,566
Other operational expenses			194			43			—			—			237
Derivative expense, net			—			1,684			—			—			1,684
Total operating expenses			61,523			132,741			(1	)		—			194,263
Income (loss) from operations			(24,713	)		87,134			1			—			62,422
Other (income) expenses:
Interest expense			7,922			—			—			—			7,922
Interest income			(1,234	)		(69	)		(8	)		—			(1,311	)
Other income			(230	)		(552	)		—			—			(782	)
Income from investment in subsidiaries			(56,166	)		—			(7	)		56,173			—
Total other (income) expenses			(49,708	)		(621	)		(15	)		56,173			5,829
Income before taxes			24,995			87,755			16			(56,173	)		56,593
Provision (benefit) for income taxes:
Current			(88	)		—			—			—			(88	)
Deferred			(11,019	)		31,598			—			—			20,579
Total income taxes			(11,107	)		31,598			—			—			20,491
Net income		$	36,102		$	56,157		$	16		($	56,173	)	$	36,102
Comprehensive income		$	17,985		$	56,157		$	16		($	56,173	)	$	17,985
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS
THREE MONTHS ENDED SEPTEMBER 30, 2012
(In thousands)
		Parent			Guarantor			Non-			Eliminations			Consolidated
					Subsidiary			Guarantor
								Subsidiaries
Operating revenue:
Oil production		$	7,682		$	173,124		$	—		$	—		$	180,806
Gas production			9,197			24,806			—			—			34,003
Natural gas liquids production			5,436			6,474			—			—			11,910
Other operational income			568			(1	)		111			—			678
Total operating revenue			22,883			204,403			111			—			227,397
Operating expenses:
Lease operating expenses			5,886			55,107			2			—			60,995
Transportation, processing and gathering expenses			4,163			2,599			—			—			6,762
Production taxes			684			1,158			—			—			1,842
Depreciation, depletion, amortization			19,336			69,939			(1	)		—			89,274
Accretion expense			138			8,181			86			—			8,405
Salaries, general and administrative			13,672			1			—			—			13,673
Incentive compensation expense			67			—			—			—			67
Other operational expenses			61			21			—						82
Derivative expense, net			—			1,812			—			—			1,812
Total operating expenses			44,007			138,818			87			—			182,912
Income (loss) from operations			(21,124	)		65,585			24			—			44,485
Other (income) expenses:
Interest expense			7,671			21			—			—			7,692
Interest income			(112	)		(5	)		—			—			(117	)
Other income			(98	)		(345	)		—			—			(443	)
Income from investment in subsidiaries			(42,200	)		(24	)		—			42,224			—
Total other (income) expenses			(34,739	)		(353	)		—			42,224			7,132
Income before taxes			13,615			65,938			24			(42,224	)		37,353
Provision (benefit) for income taxes:
Current			595			—			—			—			595
Deferred			(10,639	)		23,738			—			—			13,099
Total income taxes			(10,044	)		23,738			—			—			13,694
Net income		$	23,659		$	42,200		$	24		($	42,224	)	$	23,659
Comprehensive income (loss)		($	9,507	)	$	42,200		$	24		($	42,224	)	($	9,507	)
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS
NINE MONTHS ENDED SEPTEMBER 30, 2013
(In thousands)
		Parent			Guarantor			Non-			Eliminations			Consolidated
					Subsidiary			Guarantor
								Subsidiaries
Operating revenue:
Oil production		$	20,625		$	537,406		$	—		$	—		$	558,031
Gas production			47,240			90,142			—			—			137,382
Natural gas liquids production			17,901			18,953			—			—			36,854
Other operational income			2,150			509			—			—			2,659
Total operating revenue			87,916			647,010			—			—			734,926
Operating expenses:
Lease operating expenses			9,611			147,936			—			—			157,547
Transportation, processing and gathering expenses			17,853			9,521			—			—			27,374
Production taxes			3,960			7,444			—			—			11,404
Depreciation, depletion, amortization			62,007			193,490			—			—			255,497
Accretion expense			279			24,733			—			—			25,012
Salaries, general and administrative			43,300			4			47			—			43,351
Incentive compensation expense			8,047			—			—			—			8,047
Other operational expenses			295			87			—			—			382
Derivative expense, net			—			1,537			—			—			1,537
Total operating expenses			145,352			384,752			47			—			530,151
Income (loss) from operations			(57,436	)		262,258			(47	)		—			204,775
Other (income) expenses:
Interest expense			26,431			21			—			—			26,452
Interest income			(1,384	)		(144	)		(15	)		—			(1,543	)
Other income			(671	)		(1,519	)		—			—			(2,190	)
(Income) loss from investment in subsidiaries			(168,887	)		—			32			168,855			—
Total other (income) expenses			(144,511	)		(1,642	)		17			168,855			22,719
Income (loss) before taxes			87,075			263,900			(64	)		(168,855	)		182,056
Provision (benefit) for income taxes:
Current			(10,827	)		—			—			—			(10,827	)
Deferred			(17,980	)		94,981			—			—			77,001
Total income taxes			(28,807	)		94,981			—			—			66,174
Net income (loss)		$	115,882		$	168,919		($	64	)	($	168,855	)	$	115,882
Comprehensive income (loss)		$	93,462		$	168,919		($	64	)	($	168,855	)	$	93,462
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS
NINE MONTHS ENDED SEPTEMBER 30, 2012
(In thousands)
		Parent			Guarantor			Non-			Eliminations			Consolidated
					Subsidiary			Guarantor
								Subsidiaries
Operating revenue:
Oil production		$	20,729		$	544,016		$	—		$	—		$	564,745
Gas production			20,693			70,313			—			—			91,006
Natural gas liquids production			11,010			24,218			—			—			35,228
Other operational income			2,024			139			357			—			2,520
Derivative income, net			—			3,119			—			—			3,119
Total operating revenue			54,456			641,805			357			—			696,618
Operating expenses:
Lease operating expenses			17,108			139,937			(15	)		—			157,030
Transportation, processing and gathering expenses			8,361			7,550			—			—			15,911
Production taxes			2,354			5,224			—			—			7,578
Depreciation, depletion, amortization			45,884			214,908			190			—			260,982
Accretion expense			423			24,246			257			—			24,926
Salaries, general and administrative			40,516			5			—			—			40,521
Incentive compensation expense			3,907			—			—			—			3,907
Other operational expenses			150			45			—			—			195
Total operating expenses			118,703			391,915			432			—			511,050
Income (loss) from operations			(64,247	)		249,890			(75	)		—			185,568
Other (income) expenses:
Interest expense			21,189			(82	)		—			—			21,107
Interest income			(216	)		(11	)		—			—			(227	)
Other income			(121	)		(1,108	)		—			—			(1,229	)
(Income) loss from investment in subsidiaries			(160,650	)		75			—			160,575			—
Total other (income) expenses			(139,798	)		(1,126	)		—			160,575			19,651
Income (loss) before taxes			75,551			251,016			(75	)		(160,575	)		165,917
Provision (benefit) for income taxes:
Current			1,164			—			—			—			1,164
Deferred			(30,793	)		90,366			—			—			59,573
Total income taxes			(29,629	)		90,366			—			—			60,737
Net income (loss)		$	105,180		$	160,650		($	75	)	($	160,575	)	$	105,180
Comprehensive income (loss)		$	113,151		$	160,650		($	75	)	($	160,575	)	$	113,151
CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
NINE MONTHS ENDED SEPTEMBER 30, 2013
(In thousands)
		Parent			Guarantor			Non-			Eliminations			Consolidated
					Subsidiary			Guarantor
								Subsidiaries
Cash flows from operating activities:
Net income (loss)		$	115,882		$	168,919			($64)			($168,855)		$	115,882
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion and amortization			62,007			193,490			—			—			255,497
Accretion expense			279			24,733			—			—			25,012
Deferred income tax provision (benefit)			(17,980	)		94,981			—			—			77,001
Settlement of asset retirement obligations			—			(61,178	)		—			—			(61,178	)
Non-cash stock compensation expense			7,583			—			—			—			7,583
Excess tax benefits			(156	)		—			—			—			(156	)
Non-cash derivative expense			—			1,626			—			—			1,626
Non-cash interest expense			12,384			—			—			—			12,384
Non-cash (income) loss from investment in subsidiaries			(168,887	)		—			32			168,855			—
Change in current income taxes			(704	)		—			—			—			(704	)
Change in intercompany receivables/payables			207,267			(207,311	)		44			—			—
(Increase) decrease in accounts receivable			(24,053	)		1,776			—			—			(22,277	)
Decrease in other current assets			2,187			—			—			—			2,187
Decrease in inventory			158			—			—			—			158
Increase in accounts payable			2,610			5,425			—			—			8,035
Increase in other current liabilities			13,613			6,638			—			—			20,251
Other			499			(2,290	)		—			—			(1,791	)
Net cash provided by operating activities			212,689			226,809			12			—			439,510
Cash flows from investing activities:
Investment in oil and gas properties			(234,776	)		(226,695	)		(10,833	)		—			(472,304	)
Proceeds from sale of oil and gas properties, net of expenses			6,300			—			—			—			6,300
Investment in fixed and other assets			(3,830	)		—			—			—			(3,830	)
Change in restricted funds			—			—			(2,394	)		—			(2,394	)
Investment in subsidiaries			(14,000	)		—			(13,404	)		27,404			—
Net cash used in investing activities			(246,306	)		(226,695	)		(26,631	)		27,404			(472,228	)
Cash flows from financing activities:
Deferred financing costs			(11	)		—			—			—			(11	)
Excess tax benefits			156			—			—			—			156
Equity proceeds from parent			—			—			27,404			(27,404	)		—
Net payments for share-based compensation			(3,733	)		—			—			—			(3,733	)
Net cash (used in) provided by financing activities			(3,588	)		—			27,404			(27,404	)		(3,588	)
Effect of exchange rate changes on cash			—			—			(145	)		—			(145	)
Net change in cash and cash equivalents			(37,205	)		114			640			—			(36,451	)
Cash and cash equivalents, beginning of period			228,398			51,128			—			—			279,526
Cash and cash equivalents, end of period		$	191,193		$	51,242		$	640		$	—		$	243,075
CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
NINE MONTHS ENDED SEPTEMBER 30, 2012
(In thousands)
		Parent			Guarantor			Non-			Eliminations			Consolidated
					Subsidiary			Guarantor
								Subsidiaries
Cash flows from operating activities:
Net income (loss)		$	105,180		$	160,650			($75)			($160,575)		$	105,180
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion and amortization			45,884			214,908			190			—			260,982
Accretion expense			423			24,246			257			—			24,926
Deferred income tax provision (benefit)			(30,793	)		90,366			—			—			59,573
Settlement of asset retirement obligations			—			(47,211	)		—			—			(47,211	)
Non-cash stock compensation expense			6,800			—			—			—			6,800
Excess tax benefits			(882	)		—			—			—			(882	)
Non-cash derivative income			—			(584	)		—			—			(584	)
Non-cash interest expense			9,068			—			—			—			9,068
Other non-cash expense			16			—									16
Change in current income taxes			(3,240	)		—			—			—			(3,240	)
Change in intercompany receivables/payables			207,166			(206,669	)		(497	)		—			—
(Increase) decrease in accounts receivable			(9,229	)		(6,631	)		28			—			(15,832	)
Increase in other current assets			(2,456	)		—			—			—			(2,456	)
Decrease in inventory			136			—			—			—			136
Increase (decrease) in accounts payable			5,733			422			(39	)		—			6,116
Decrease in other current liabilities			(20,441	)		(3,860	)		—			—			(24,301	)
Other			(163,921	)		(1,032	)		—			160,575			(4,378	)
Net cash provided by (used in) operating activities			149,444			224,605			(136	)		—			373,913
Cash flows from investing activities:
Investment in oil and gas properties			(240,877	)		(204,434	)		—			—			(445,311	)
Proceeds from sale of oil and gas properties, net of expenses			403			—			—			—			403
Sale of fixed assets			134			—			—			—			134
Investment in fixed and other assets			(3,998	)		—			—			—			(3,998	)
Net cash used in investing activities			(244,338	)		(204,434	)		—			—			(448,772	)
Cash flows from financing activities:
Proceeds from bank borrowings			25,000			—			—			—			25,000
Repayments of bank borrowings			(70,000	)		—			—			—			(70,000	)
Proceeds from issuance of senior convertible notes			300,000			—			—			—			300,000
Deferred financing costs of senior convertible notes			(8,855	)		—			—			—			(8,855	)
Proceeds from sold warrants			40,170			—			—			—			40,170
Payments for purchased call options			(70,830	)		—			—			—			(70,830	)
Excess tax benefits			882			—			—			—			882
Net payments for share-based compensation			(3,773	)		—			—			—			(3,773	)
Net cash provided by financing activities			212,594			—			—			—			212,594
Net change in cash and cash equivalents			117,700			20,171			(136	)		—			137,735
Cash and cash equivalents, beginning of period			37,389			926			136			—			38,451
Cash and cash equivalents, end of period		$	155,089		$	21,097		$	—		$	—		$	176,186

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Calculation of Basic and Diluted Weighted Average Shares Outstanding Earnings Per Share	'
	The following table sets forth the calculation of basic and diluted weighted average shares outstanding and earnings per share for the indicated periods.
		Three Months Ended						Nine Months Ended
		September 30,						September 30,
		2013			2012			2013			2012
		(In thousands, except per share amounts)
	Income (numerator):
	Basic:
	Net income	$	36,102		$	23,659		$	115,882		$	105,180
	Net income attributable to participating securities		(924	)		(564	)		(2,728	)		(2,283	)
	Net income attributable to common stock—basic	$	35,178		$	23,095		$	113,154		$	102,897
	Diluted:
	Net income	$	36,102		$	23,659		$	115,882		$	105,180
	Net income attributable to participating securities		(923	)		(563	)		(2,726	)		(2,281	)
	Net income attributable to common stock—diluted	$	35,179		$	23,096		$	113,156		$	102,899
	Weighted average shares (denominator):
	Weighted average shares—basic		48,732			48,342			48,680			48,300
	Dilutive effect of stock options		44			42			40			43
	Weighted average shares—diluted		48,776			48,384			48,720			48,343
	Basic earnings per share	$	0.72		$	0.48		$	2.32		$	2.13
	Diluted earnings per share	$	0.72		$	0.48		$	2.32		$	2.13

Derivative_Instruments_and_Hed1

Derivative Instruments and Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2013
Derivative Instruments And Hedging Activities Disclosure [Abstract]	'
Location and Fair Value Amounts of Derivative Instruments Reported in Balance Sheet	'
	The following tables disclose the location and fair value amounts of derivative instruments reported in our balance sheet at September 30, 2013 and December 31, 2012.
	Fair Value of Derivative Instruments at September 30, 2013
	(In millions)
			Asset Derivatives						Liability Derivatives
	Description		Balance Sheet Location		Fair				Balance Sheet Location	Fair
					Value					Value
	Commodity contracts		Current assets: Fair value of hedging contracts		$	14.4			Current liabilities: Fair value of hedging contracts	($	8.3	)
			Long-term assets: Fair value of hedging contracts			5.1			Long-term liabilities: Fair value of hedging contracts		(0.3	)
					$	19.5				($	8.6	)
	Fair Value of Derivative Instruments at December 31, 2012
	(In millions)
			Asset Derivatives						Liability Derivatives
	Description		Balance Sheet Location		Fair				Balance Sheet Location	Fair
					Value					Value
	Commodity contracts		Current assets: Fair value of hedging contracts		$	39.7			Current liabilities: Fair value of hedging contracts	($	0.1	)
			Long-term assets: Fair value of hedging contracts			9.2			Long-term liabilities: Fair value of hedging contracts		(1.5	)
					$	48.9				($	1.6	)
Effect of Derivative Instruments in Statement of Operations	'
	The following tables disclose the effect of derivative instruments on the statement of operations for the three and nine month periods ended September 30, 2013 and 2012.
	Effect of Derivative Instruments on the Statement of Operations for the Three Months Ended September 30, 2013 and 2012
	(In millions)
	Derivatives in Cash		Amount of Gain							Gain (Loss) Reclassified from								Gain (Loss) Recognized in Income
	Flow Hedging		(Loss) Recognized							Accumulated Other Comprehensive Income								on Derivatives
	Relationships		in Other							into Income								(Ineffective Portion)
			Comprehensive							(Effective Portion) (a)
			Income on
			Derivatives
			2013				2012			Location		2013				2012		Location	2013			2012
	Commodity contracts		($	30.8	)		($	41.8	)	Operating revenue—		($	2.1	)		$	10	Derivative expense, net	($	1.7	)	($	1.8	)
										oil/gas production
	Total		($	30.8	)		($	41.8	)			($	2.1	)		$	10		($	1.7	)	($	1.8	)
	(a)	For the three months ended September 30, 2013, effective hedging contracts decreased oil revenue by $7.5 million and increased gas revenue by $5.4 million. For the three months ended September 30, 2012, effective hedging contracts increased oil revenue by $4.1 million and increased gas revenue by $5.9 million.
	Effect of Derivative Instruments on the Statement of Operations for the Nine Months Ended September 30, 2013 and 2012
	(In millions)
	Derivatives in Cash		Amount of Gain							Gain (Loss) Reclassified from								Gain (Loss) Recognized in Income
	Flow Hedging		(Loss) Recognized							Accumulated Other Comprehensive Income								on Derivatives
	Relationships		in Other							into Income								(Ineffective Portion)
			Comprehensive							(Effective Portion) (a)
			Income on
			Derivatives
			2013				2012			Location		2013				2012		Location	2013			2012
	Commodity contracts		($	20.9	)		$	30.8		Operating revenue—		$	13.8			$	18.4	Derivative (expense)	($	1.5	)	$	3.1
										oil/gas production								income, net
	Total		($	20.9	)		$	30.8				$	13.8			$	18.4		($	1.5	)	$	3.1
	(a)	For the nine months ended September 30, 2013, effective hedging contracts increased oil revenue by $2.4 million and increased gas revenue by $11.4 million. For the nine months ended September 30, 2012, effective hedging contracts increased oil revenue by $1.1 million and increased gas revenue by $17.3 million.
Impact of Rights of Offset Associated with Recognized Assets and Liabilities	'
	The following presents the potential impact of the rights of offset associated with our recognized assets and liabilities at September 30, 2013:
			As Presented				Effects of			With Effects
			Without				Netting			of Netting
			Netting
			(In millions)
	Current assets: Fair value of hedging contracts		$	14.4			($	5	)	$	9.4
	Long-term assets: Fair value of hedging contracts			5.1				(3.5	)		1.6
	Current liabilities: Fair value of hedging contracts			(8.3	)			8.2			(0.1	)
	Long-term liabilities: Fair value of hedging contracts			(0.3	)			0.3			—
Hedging Positions	'
	The following table illustrates our hedging positions for calendar years 2013, 2014 and 2015 as of November 5, 2013:
			Fixed-Price Swaps
			NYMEX (except where noted)
			Natural Gas							Oil
			Daily Volume				Swap			Daily Volume				Swap
			(MMBtus/d)				Price ($)			(Bbls/d)				Price ($)
	2013			10,000				4			2,000	(a)			92.35
	2013			10,000	(b)			4.05			1,000				92.8
	2013			20,000	(a)			4.45			2,000	(c)			94.05
	2013			10,000				5.27			1,000				94.45
	2013			10,000				5.32			1,000				94.6
	2013										1,000				97.15
	2013										1,000				101.53
	2013										1,000				103
	2013										1,000				103.15
	2013										1,000				104.25
	2013										1,000				104.47
	2013										1,000				104.5
	2013										1,000	(d)			107.3
	2014			10,000				4			1,000				90.06
	2014			10,000				4.04			1,000				92.25
	2014			10,000				4.105			1,000				93.55
	2014			10,000				4.19			1,000				94
	2014			10,000				4.25			1,000				98
	2014			10,000				4.35			1,000				98.3
	2014										2,000	(c)			98.85
	2014										1,000				99.65
	2014										1,000	(d)			103.3
	2015			10,000				4.005			1,000				90
	2015			10,000				4.22
	2015			10,000				4.255
	(a)	July through December
	(b)	April through December
	(c)	January through June
	(d)	Brent crude oil contract

LongTerm_Debt_Tables

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Long-Term Debt	'
	Long-term debt consisted of the following at:
		September 30,		December 31,
		2013		2012
		(In millions)
	8 5⁄8% Senior Notes due 2017	$	375	$	375
	1 3⁄4% Senior Convertible Notes due 2017		248.7		239.1
	7 1⁄2% Senior Notes due 2022		300		300
	Bank debt		—		—
	Total long-term debt	$	923.7	$	914.1

Asset_Retirement_Obligations_T

Asset Retirement Obligations (Tables)	9 Months Ended
	Sep. 30, 2013
Asset Retirement Obligation Disclosure [Abstract]	'
Changes in Asset Retirement Obligations	'
	The change in our asset retirement obligations during the nine months ended September 30, 2013 is set forth below:
		Nine Months
		Ended
		September 30,
		2013
		(In millions)
	Asset retirement obligations as of the beginning of the period, including current portion	$	488.3
	Liabilities incurred		16.5
	Liabilities settled		(61.2	)
	Accretion expense		25
	Asset retirement obligations as of the end of the period, including current portion	$	468.6

Acquisitions_Tables

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2013
Business Combinations [Abstract]	'
Allocation of Recorded Value of Net Assets Acquired in Transaction	'
	The following represents the allocation of the recorded value of net assets acquired in the transaction.
		(In millions)
	Proved oil and gas properties	$	39.2
	Unevaluated oil and gas properties		1.6
	Asset retirement obligations		(14.4	)
	Total fair value of net assets	$	26.4

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Schedule of Assets And Liabilities Measured at Fair Value Recurring Basis	'
	The following tables present our assets and liabilities that are measured at fair value on a recurring basis at September 30, 2013:
		Fair Value Measurements at September 30, 2013
	Assets	Total			Quoted Prices		Significant			Significant
					in Active		Other			Unobservable
					Markets for		Observable			Inputs
					Identical Assets		Inputs			(Level 3)
					(Level 1)		(Level 2)
		(In millions)
	Marketable securities	$	8		$	8	$	—		$	—
	Hedging contracts		19.5			—		19.5			—
	Total	$	27.5		$	8	$	19.5		$	—
		Fair Value Measurements at September 30, 2013
	Liabilities	Total			Quoted Prices		Significant			Significant
					in Active		Other			Unobservable
					Markets for		Observable			Inputs
					Identical		Inputs			(Level 3)
					Liabilities		(Level 2)
					(Level 1)
		(In millions)
	Hedging contracts	($	8.6	)	$	—	($	8.6	)	$	—
	Total	($	8.6	)	$	—	($	8.6	)	$	—
	The following tables present our assets and liabilities that are measured at fair value on a recurring basis at December 31, 2012:
		Fair Value Measurements at December 31, 2012
	Assets	Total			Quoted Prices		Significant			Significant
					in Active		Other			Unobservable
					Markets for		Observable			Inputs
					Identical Assets		Inputs			(Level 3)
					(Level 1)		(Level 2)
		(In millions)
	Marketable securities	$	13.5		$	13.5	$	—		$	—
	Hedging contracts		48.9			—		48.9			—
	Total	$	62.4		$	13.5	$	48.9		$	—
		Fair Value Measurements at December 31, 2012
	Liabilities	Total			Quoted Prices		Significant			Significant
					in Active		Other			Unobservable
					Markets for		Observable			Inputs
					Identical		Inputs			(Level 3)
					Liabilities		(Level 2)
					(Level 1)
		(In millions)
	Hedging contracts	($	1.6	)	$	—	($	1.6	)	$	—
	Total	($	1.6	)	$	—	($	1.6	)	$	—

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Loss) (Tables)	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Schedule of Changes In Accumulated Other Comprehensive Income Loss	'
	Changes in accumulated other comprehensive income (loss) by component for the three and nine month periods ended September 30, 2013 were as follows (in millions):
		Cash Flow			Foreign			Total
		Hedges			Currency
					Items
	For the Three Months Ended September 30, 2013
	Beginning balance, net of tax	$	25		($	0.5	)	$	24.5
	Other comprehensive income (loss) before reclassifications:
	Change in fair value of derivatives		(30.8	)		—			(30.8	)
	Foreign currency translations		—			0.3			0.3
	Income tax effect		11.1			—			11.1
	Net of tax		(19.7	)		0.3			(19.4	)
	Amounts reclassified from accumulated other comprehensive income:
	Operating revenue: oil/gas production		2.1			—			2.1
	Income tax effect		(0.8	)		—			(0.8	)
	Net of tax		1.3			—			1.3
	Other comprehensive income (loss), net of tax		(18.4	)		0.3			(18.1	)
	Ending balance, net of tax	$	6.6		($	0.2	)	$	6.4
	For the Nine Months Ended September 30, 2013
	Beginning balance, net of tax	$	28.8		$	—		$	28.8
	Other comprehensive income (loss) before reclassifications:
	Change in fair value of derivatives		(20.9	)		—			(20.9	)
	Foreign currency translations		—			(0.2	)		(0.2	)
	Income tax effect		7.6			—			7.6
	Net of tax		(13.3	)		(0.2	)		(13.5	)
	Amounts reclassified from accumulated other comprehensive income:
	Operating revenue: oil/gas production		(13.8	)		—			(13.8	)
	Income tax effect		4.9			—			4.9
	Net of tax		(8.9	)		—			(8.9	)
	Other comprehensive income (loss), net of tax		(22.2	)		(0.2	)		(22.4	)
	Ending balance, net of tax	$	6.6		($	0.2	)	$	6.4
	In 2012, the only component of accumulated other comprehensive income (loss) related to our cash flow hedges. Changes in accumulated other comprehensive income (loss) for the three and nine month periods ended September 30, 2012 were as follows (in millions):
		Cash Flow
		Hedges
	For the Three Months Ended September 30, 2012
	Beginning balance, net of tax	$	63
	Other comprehensive income (loss) before reclassifications:
	Change in fair value of derivatives		(41.8	)
	Income tax effect		15
	Net of tax		(26.8	)
	Amounts reclassified from accumulated other comprehensive income:
	Operating revenue: oil/gas production		(10.0	)
	Income tax effect		3.6
	Net of tax		(6.4	)
	Other comprehensive income, net of tax		(33.2	)
	Ending balance, net of tax	$	29.8

Guarantor_Financial_Statements1

Guarantor Financial Statements (Tables)	9 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Condensed Consolidating Balance Sheet	'
	CONDENSED CONSOLIDATING BALANCE SHEET
	30-Sep-13
	(In thousands)
			Parent			Guarantor			Non-Guarantor			Eliminations			Consolidated
						Subsidiary			Subsidiaries
	Assets
	Current assets:
	Cash and cash equivalents		$	191,193		$	51,242		$	640		$	—		$	243,075
	Accounts receivable			83,310			313,610			—			(207,355	)		189,565
	Fair value of hedging contracts			—			14,423			—			—			14,423
	Current income tax receivable			10,893			—			—			—			10,893
	Deferred taxes *			6,631			19,719			—			—			26,350
	Inventory			3,560			283			—			—			3,843
	Other current assets			1,439			—			—			—			1,439
	Total current assets			297,026			399,277			640			(207,355	)		489,588
	Oil and gas properties, full cost method: Proved			1,211,964			6,377,189			—			—			7,589,153
	Less: accumulated DD&A			(429,380	)		(5,333,557	)		—			—			(5,762,937	)
	Net proved oil and gas properties			782,584			1,043,632			—			—			1,826,216
	Unevaluated			274,986			291,750			9,659			—			576,395
	Other property and equipment, net			23,965			—			—			—			23,965
	Fair value of hedging contracts			—			5,114			—			—			5,114
	Other assets, net			44,324			1,349			3,475			—			49,148
	Investment in subsidiary			896,798			—			13,116			(909,914	)		—
	Total assets		$	2,319,683		$	1,741,122		$	26,890		($	1,117,269	)	$	2,970,426
	Liabilities and Stockholders’ Equity
	Current liabilities:
	Accounts payable to vendors		$	289,204		$	22,576		$	61		($	207,355	)	$	104,486
	Undistributed oil and gas proceeds			39,141			3,772			—			—			42,913
	Accrued interest			14,272			—			—			—			14,272
	Fair value of hedging contracts			—			8,261			—			—			8,261
	Asset retirement obligations			—			60,938			—			—			60,938
	Other current liabilities			17,242			4,438			—			—			21,680
	Total current liabilities			359,859			99,985			61			(207,355	)		252,550
	Long-term debt			923,745			—			—			—			923,745
	Deferred taxes *			31,295			355,738			—			—			387,033
	Asset retirement obligations			5,758			401,954			—			—			407,712
	Fair value of hedging contracts			—			360			—			—			360
	Other long-term liabilities			26,463			—			—			—			26,463
	Total liabilities			1,347,120			858,037			61			(207,355	)		1,997,863
	Commitments and contingencies
	Stockholders’ equity:
	Common stock			488			—			—			—			488
	Treasury stock			(860	)		—			—			—			(860	)
	Additional paid-in capital			1,393,439			1,496,509			27,404			(1,523,913	)		1,393,439
	Accumulated deficit			(426,917	)		(620,093	)		(64	)		620,157			(426,917	)
	Accumulated other comprehensive income (loss)			6,413			6,669			(511	)		(6,158	)		6,413
	Total stockholders’ equity			972,563			883,085			26,829			(909,914	)		972,563
	Total liabilities and stockholders’ equity		$	2,319,683		$	1,741,122		$	26,890		($	1,117,269	)	$	2,970,426
	*	Deferred income taxes have been allocated to the Guarantor Subsidiary where related oil and gas properties reside.
	CONDENSED CONSOLIDATING BALANCE SHEET
	31-Dec-12
	(In thousands)
			Parent			Guarantor			Non-Guarantor			Eliminations			Consolidated
						Subsidiary			Subsidiaries
	Assets
	Current assets:
	Cash and cash equivalents		$	228,398		$	51,128		$	—		$	—		$	279,526
	Accounts receivable			59,213			108,075			—			—			167,288
	Fair value of hedging contracts			—			39,655			—			—			39,655
	Current income tax receivable			10,027			—			—			—			10,027
	Deferred taxes *			5,947			9,567			—			—			15,514
	Inventory			3,924			283			—			—			4,207
	Other current assets			3,626			—			—			—			3,626
Total current assets			311,135			208,708			—			—			519,843
Oil and gas properties, full cost method: Proved			1,004,808			6,239,658			—			—			7,244,466
Less: accumulated DD&A			(370,111	)		(5,140,055	)		—			—			(5,510,166	)
Net proved oil and gas properties			634,697			1,099,603			—			—			1,734,300
Unevaluated			254,757			193,038			—			—			447,795
Other property and equipment, net			22,115			—			—			—			22,115
Fair value of hedging contracts			—			9,199			—			—			9,199
Other assets, net			41,679			1,500			—			—			43,179
Investment in subsidiary			736,331			—			—			(736,331	)		—
Total assets		$	2,000,714		$	1,512,048		$	—		($	736,331	)	$	2,776,431
Liabilities and Stockholders’ Equity
Current liabilities:
Accounts payable to vendors		$	74,503		$	19,858		$	—		$	—		$	94,361
Undistributed oil and gas proceeds			21,841			1,573			—			—			23,414
Accrued interest			18,546			—			—			—			18,546
Fair value of hedging contracts			—			149			—			—			149
Asset retirement obligations			—			66,260			—			—			66,260
Other current liabilities			16,765			—			—			—			16,765
Total current liabilities			131,655			87,840			—			—			219,495
Long-term debt			914,126			—			—			—			914,126
Deferred taxes *			47,758			263,072			—			—			310,830
Asset retirement obligations			5,479			416,563			—			—			422,042
Fair value of hedging contracts			—			1,530			—			—			1,530
Other long-term liabilities			29,563			6,712			—			—			36,275
Total liabilities			1,128,581			775,717			—			—			1,904,298
Commitments and contingencies
Stockholders’ equity:
Common stock			484			—			—			—			484
Treasury stock			(860	)		—			—			—			(860	)
Additional paid-in capital			1,386,475			1,496,510			—			(1,496,510	)		1,386,475
Accumulated deficit			(542,799	)		(789,012	)		—			789,012			(542,799	)
Accumulated other comprehensive income			28,833			28,833			—			(28,833	)		28,833
Total stockholders’ equity			872,133			736,331			—			(736,331	)		872,133
Total liabilities and stockholders’ equity		$	2,000,714		$	1,512,048		$	—		($	736,331	)	$	2,776,431
*	Deferred income taxes have been allocated to the Guarantor Subsidiary where related oil and gas properties reside.
Condensed Consolidating Statement of Operations	'
	CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS
	THREE MONTHS ENDED SEPTEMBER 30, 2013
	(In thousands)
			Parent			Guarantor			Non-			Eliminations			Consolidated
						Subsidiary			Guarantor
									Subsidiaries
	Operating revenue:
	Oil production		$	6,904		$	179,704		$	—		$	—		$	186,608
	Gas production			19,971			32,757			—			—			52,728
	Natural gas liquids production			9,224			7,252			—			—			16,476
	Other operational income			711			162			—			—			873
	Total operating revenue			36,810			219,875			—			—			256,685
	Operating expenses:
	Lease operating expenses			3,895			50,091			—			—			53,986
	Transportation, processing and gathering expenses			10,072			3,009			—			—			13,081
	Production taxes			1,773			3,451			—			—			5,224
	Depreciation, depletion, amortization			26,728			66,125			—			—			92,853
	Accretion expense			93			8,338			—			—			8,431
	Salaries, general and administrative			14,202			—			(1	)		—			14,201
	Incentive compensation expense			4,566			—			—			—			4,566
	Other operational expenses			194			43			—			—			237
	Derivative expense, net			—			1,684			—			—			1,684
	Total operating expenses			61,523			132,741			(1	)		—			194,263
	Income (loss) from operations			(24,713	)		87,134			1			—			62,422
	Other (income) expenses:
	Interest expense			7,922			—			—			—			7,922
	Interest income			(1,234	)		(69	)		(8	)		—			(1,311	)
	Other income			(230	)		(552	)		—			—			(782	)
	Income from investment in subsidiaries			(56,166	)		—			(7	)		56,173			—
	Total other (income) expenses			(49,708	)		(621	)		(15	)		56,173			5,829
	Income before taxes			24,995			87,755			16			(56,173	)		56,593
	Provision (benefit) for income taxes:
	Current			(88	)		—			—			—			(88	)
	Deferred			(11,019	)		31,598			—			—			20,579
	Total income taxes			(11,107	)		31,598			—			—			20,491
	Net income		$	36,102		$	56,157		$	16		($	56,173	)	$	36,102
	Comprehensive income		$	17,985		$	56,157		$	16		($	56,173	)	$	17,985
	CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS
	THREE MONTHS ENDED SEPTEMBER 30, 2012
	(In thousands)
			Parent			Guarantor			Non-			Eliminations			Consolidated
						Subsidiary			Guarantor
									Subsidiaries
	Operating revenue:
	Oil production		$	7,682		$	173,124		$	—		$	—		$	180,806
	Gas production			9,197			24,806			—			—			34,003
	Natural gas liquids production			5,436			6,474			—			—			11,910
	Other operational income			568			(1	)		111			—			678
	Total operating revenue			22,883			204,403			111			—			227,397
	Operating expenses:
	Lease operating expenses			5,886			55,107			2			—			60,995
	Transportation, processing and gathering expenses			4,163			2,599			—			—			6,762
	Production taxes			684			1,158			—			—			1,842
	Depreciation, depletion, amortization			19,336			69,939			(1	)		—			89,274
	Accretion expense			138			8,181			86			—			8,405
	Salaries, general and administrative			13,672			1			—			—			13,673
	Incentive compensation expense			67			—			—			—			67
	Other operational expenses			61			21			—						82
	Derivative expense, net			—			1,812			—			—			1,812
	Total operating expenses			44,007			138,818			87			—			182,912
	Income (loss) from operations			(21,124	)		65,585			24			—			44,485
	Other (income) expenses:
	Interest expense			7,671			21			—			—			7,692
Interest income			(112	)		(5	)		—			—			(117	)
Other income			(98	)		(345	)		—			—			(443	)
Income from investment in subsidiaries			(42,200	)		(24	)		—			42,224			—
Total other (income) expenses			(34,739	)		(353	)		—			42,224			7,132
Income before taxes			13,615			65,938			24			(42,224	)		37,353
Provision (benefit) for income taxes:
Current			595			—			—			—			595
Deferred			(10,639	)		23,738			—			—			13,099
Total income taxes			(10,044	)		23,738			—			—			13,694
Net income		$	23,659		$	42,200		$	24		($	42,224	)	$	23,659
Comprehensive income (loss)		($	9,507	)	$	42,200		$	24		($	42,224	)	($	9,507	)
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS
NINE MONTHS ENDED SEPTEMBER 30, 2013
(In thousands)
		Parent			Guarantor			Non-			Eliminations			Consolidated
					Subsidiary			Guarantor
								Subsidiaries
Operating revenue:
Oil production		$	20,625		$	537,406		$	—		$	—		$	558,031
Gas production			47,240			90,142			—			—			137,382
Natural gas liquids production			17,901			18,953			—			—			36,854
Other operational income			2,150			509			—			—			2,659
Total operating revenue			87,916			647,010			—			—			734,926
Operating expenses:
Lease operating expenses			9,611			147,936			—			—			157,547
Transportation, processing and gathering expenses			17,853			9,521			—			—			27,374
Production taxes			3,960			7,444			—			—			11,404
Depreciation, depletion, amortization			62,007			193,490			—			—			255,497
Accretion expense			279			24,733			—			—			25,012
Salaries, general and administrative			43,300			4			47			—			43,351
Incentive compensation expense			8,047			—			—			—			8,047
Other operational expenses			295			87			—			—			382
Derivative expense, net			—			1,537			—			—			1,537
Total operating expenses			145,352			384,752			47			—			530,151
Income (loss) from operations			(57,436	)		262,258			(47	)		—			204,775
Other (income) expenses:
Interest expense			26,431			21			—			—			26,452
Interest income			(1,384	)		(144	)		(15	)		—			(1,543	)
Other income			(671	)		(1,519	)		—			—			(2,190	)
(Income) loss from investment in subsidiaries			(168,887	)		—			32			168,855			—
Total other (income) expenses			(144,511	)		(1,642	)		17			168,855			22,719
Income (loss) before taxes			87,075			263,900			(64	)		(168,855	)		182,056
Provision (benefit) for income taxes:
Current			(10,827	)		—			—			—			(10,827	)
Deferred			(17,980	)		94,981			—			—			77,001
Total income taxes			(28,807	)		94,981			—			—			66,174
Net income (loss)		$	115,882		$	168,919		($	64	)	($	168,855	)	$	115,882
Comprehensive income (loss)		$	93,462		$	168,919		($	64	)	($	168,855	)	$	93,462
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS
NINE MONTHS ENDED SEPTEMBER 30, 2012
(In thousands)
		Parent			Guarantor			Non-			Eliminations			Consolidated
					Subsidiary			Guarantor
								Subsidiaries
Operating revenue:
Oil production		$	20,729		$	544,016		$	—		$	—		$	564,745
Gas production			20,693			70,313			—			—			91,006
Natural gas liquids production			11,010			24,218			—			—			35,228
Other operational income			2,024			139			357			—			2,520
Derivative income, net			—			3,119			—			—			3,119
Total operating revenue			54,456			641,805			357			—			696,618
Operating expenses:
Lease operating expenses			17,108			139,937			(15	)		—			157,030
Transportation, processing and gathering expenses			8,361			7,550			—			—			15,911
Production taxes			2,354			5,224			—			—			7,578
Depreciation, depletion, amortization			45,884			214,908			190			—			260,982
Accretion expense			423			24,246			257			—			24,926
Salaries, general and administrative			40,516			5			—			—			40,521
Incentive compensation expense			3,907			—			—			—			3,907
Other operational expenses			150			45			—			—			195
Total operating expenses			118,703			391,915			432			—			511,050
Income (loss) from operations			(64,247	)		249,890			(75	)		—			185,568
Other (income) expenses:
Interest expense			21,189			(82	)		—			—			21,107
Interest income			(216	)		(11	)		—			—			(227	)
Other income			(121	)		(1,108	)		—			—			(1,229	)
(Income) loss from investment in subsidiaries			(160,650	)		75			—			160,575			—
Total other (income) expenses			(139,798	)		(1,126	)		—			160,575			19,651
Income (loss) before taxes			75,551			251,016			(75	)		(160,575	)		165,917
Provision (benefit) for income taxes:
Current			1,164			—			—			—			1,164
Deferred			(30,793	)		90,366			—			—			59,573
Total income taxes			(29,629	)		90,366			—			—			60,737
Net income (loss)		$	105,180		$	160,650		($	75	)	($	160,575	)	$	105,180
Comprehensive income (loss)		$	113,151		$	160,650		($	75	)	($	160,575	)	$	113,151
Condensed Consolidating Statement of Cash Flows	'
	CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
	NINE MONTHS ENDED SEPTEMBER 30, 2013
	(In thousands)
			Parent			Guarantor			Non-			Eliminations			Consolidated
						Subsidiary			Guarantor
									Subsidiaries
	Cash flows from operating activities:
	Net income (loss)		$	115,882		$	168,919			($64)			($168,855)		$	115,882
	Adjustments to reconcile net income (loss) to net cash provided by operating activities:
	Depreciation, depletion and amortization			62,007			193,490			—			—			255,497
	Accretion expense			279			24,733			—			—			25,012
	Deferred income tax provision (benefit)			(17,980	)		94,981			—			—			77,001
	Settlement of asset retirement obligations			—			(61,178	)		—			—			(61,178	)
	Non-cash stock compensation expense			7,583			—			—			—			7,583
	Excess tax benefits			(156	)		—			—			—			(156	)
	Non-cash derivative expense			—			1,626			—			—			1,626
	Non-cash interest expense			12,384			—			—			—			12,384
	Non-cash (income) loss from investment in subsidiaries			(168,887	)		—			32			168,855			—
	Change in current income taxes			(704	)		—			—			—			(704	)
	Change in intercompany receivables/payables			207,267			(207,311	)		44			—			—
	(Increase) decrease in accounts receivable			(24,053	)		1,776			—			—			(22,277	)
	Decrease in other current assets			2,187			—			—			—			2,187
	Decrease in inventory			158			—			—			—			158
	Increase in accounts payable			2,610			5,425			—			—			8,035
	Increase in other current liabilities			13,613			6,638			—			—			20,251
	Other			499			(2,290	)		—			—			(1,791	)
	Net cash provided by operating activities			212,689			226,809			12			—			439,510
	Cash flows from investing activities:
	Investment in oil and gas properties			(234,776	)		(226,695	)		(10,833	)		—			(472,304	)
	Proceeds from sale of oil and gas properties, net of expenses			6,300			—			—			—			6,300
	Investment in fixed and other assets			(3,830	)		—			—			—			(3,830	)
	Change in restricted funds			—			—			(2,394	)		—			(2,394	)
	Investment in subsidiaries			(14,000	)		—			(13,404	)		27,404			—
	Net cash used in investing activities			(246,306	)		(226,695	)		(26,631	)		27,404			(472,228	)
	Cash flows from financing activities:
	Deferred financing costs			(11	)		—			—			—			(11	)
	Excess tax benefits			156			—			—			—			156
	Equity proceeds from parent			—			—			27,404			(27,404	)		—
	Net payments for share-based compensation			(3,733	)		—			—			—			(3,733	)
	Net cash (used in) provided by financing activities			(3,588	)		—			27,404			(27,404	)		(3,588	)
	Effect of exchange rate changes on cash			—			—			(145	)		—			(145	)
	Net change in cash and cash equivalents			(37,205	)		114			640			—			(36,451	)
	Cash and cash equivalents, beginning of period			228,398			51,128			—			—			279,526
	Cash and cash equivalents, end of period		$	191,193		$	51,242		$	640		$	—		$	243,075
	CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
	NINE MONTHS ENDED SEPTEMBER 30, 2012
	(In thousands)
			Parent			Guarantor			Non-			Eliminations			Consolidated
						Subsidiary			Guarantor
									Subsidiaries
	Cash flows from operating activities:
	Net income (loss)		$	105,180		$	160,650			($75)			($160,575)		$	105,180
	Adjustments to reconcile net income (loss) to net cash provided by operating activities:
	Depreciation, depletion and amortization			45,884			214,908			190			—			260,982
	Accretion expense			423			24,246			257			—			24,926
	Deferred income tax provision (benefit)			(30,793	)		90,366			—			—			59,573
	Settlement of asset retirement obligations			—			(47,211	)		—			—			(47,211	)
	Non-cash stock compensation expense			6,800			—			—			—			6,800
	Excess tax benefits			(882	)		—			—			—			(882	)
	Non-cash derivative income			—			(584	)		—			—			(584	)
	Non-cash interest expense			9,068			—			—			—			9,068
	Other non-cash expense			16			—									16
	Change in current income taxes			(3,240	)		—			—			—			(3,240	)
Change in intercompany receivables/payables			207,166			(206,669	)		(497	)		—			—
(Increase) decrease in accounts receivable			(9,229	)		(6,631	)		28			—			(15,832	)
Increase in other current assets			(2,456	)		—			—			—			(2,456	)
Decrease in inventory			136			—			—			—			136
Increase (decrease) in accounts payable			5,733			422			(39	)		—			6,116
Decrease in other current liabilities			(20,441	)		(3,860	)		—			—			(24,301	)
Other			(163,921	)		(1,032	)		—			160,575			(4,378	)
Net cash provided by (used in) operating activities			149,444			224,605			(136	)		—			373,913
Cash flows from investing activities:
Investment in oil and gas properties			(240,877	)		(204,434	)		—			—			(445,311	)
Proceeds from sale of oil and gas properties, net of expenses			403			—			—			—			403
Sale of fixed assets			134			—			—			—			134
Investment in fixed and other assets			(3,998	)		—			—			—			(3,998	)
Net cash used in investing activities			(244,338	)		(204,434	)		—			—			(448,772	)
Cash flows from financing activities:
Proceeds from bank borrowings			25,000			—			—			—			25,000
Repayments of bank borrowings			(70,000	)		—			—			—			(70,000	)
Proceeds from issuance of senior convertible notes			300,000			—			—			—			300,000
Deferred financing costs of senior convertible notes			(8,855	)		—			—			—			(8,855	)
Proceeds from sold warrants			40,170			—			—			—			40,170
Payments for purchased call options			(70,830	)		—			—			—			(70,830	)
Excess tax benefits			882			—			—			—			882
Net payments for share-based compensation			(3,773	)		—			—			—			(3,773	)
Net cash provided by financing activities			212,594			—			—			—			212,594
Net change in cash and cash equivalents			117,700			20,171			(136	)		—			137,735
Cash and cash equivalents, beginning of period			37,389			926			136			—			38,451
Cash and cash equivalents, end of period		$	155,089		$	21,097		$	—		$	—		$	176,186

Calculation_of_Basic_and_Dilut

Calculation of Basic and Diluted Weighted Average Shares Outstanding and Earnings Per Share (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Basic:	'	'	'	'
Net income	$36,102	$23,659	$115,882	$105,180
Net income attributable to participating securities	-924	-564	-2,728	-2,283
Net income attributable to common stock-basic	35,178	23,095	113,154	102,897
Diluted:	'	'	'	'
Net income	36,102	23,659	115,882	105,180
Net income attributable to participating securities	-923	-563	-2,726	-2,281
Net income attributable to common stock-diluted	$35,179	$23,096	$113,156	$102,899
Weighted average shares (denominator):	'	'	'	'
Weighted average shares-basic	48,732	48,342	48,680	48,300
Dilutive effect of stock options	44	42	40	43
Weighted average shares-diluted	48,776	48,384	48,720	48,343
Basic earnings per share	$0.72	$0.48	$2.32	$2.13
Diluted earnings per share	$0.72	$0.48	$2.32	$2.13

Earnings_Per_Share_Additional_

Earnings Per Share - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Antidilutive stock options outstanding	327,000	369,000	327,000	369,000
Shares of common stock issued upon vesting of restricted stock	22,000	59,000	358,000	314,000
Convertible Notes Due 2017 [Member]	'	'	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'	'	'
Long-term debt	1.75%	'	1.75%	'

Derivative_Instruments_and_Hed2

Derivative Instruments and Hedging Activities - Additional Information (Detail) (USD $)	9 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012
Derivative Instruments And Hedging Activities Disclosure [Abstract]	'	'	'
Maximum correlation between price of oil & natural gas in market and underlying price basis indicative in the derivative contract	100.00%	'	'
Accumulated other comprehensive income (loss)	$6,413,000	$24,500,000	$28,833,000
Accumulated other comprehensive income, to be reclassified into earning in the next twelve months	$3,800,000	'	'

Location_and_Fair_Value_Amount

Location and Fair Value Amounts of Derivative Instruments Reported in Balance Sheet (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Current liabilities [Member]	'	'
Liability Derivatives	'	'
Fair Value of Derivative Instruments, Liabilities	($8.30)	'
Long-term liabilities [Member]	'	'
Liability Derivatives	'	'
Fair Value of Derivative Instruments, Liabilities	-0.3	'
Current Asset [Member]	'	'
Asset Derivatives	'	'
Fair Value of Derivative Instruments, Assets	14.4	'
Long-term assets [Member]	'	'
Asset Derivatives	'	'
Fair Value of Derivative Instruments, Assets	5.1	'
Commodity Contracts [Member]	'	'
Asset Derivatives	'	'
Fair Value of Derivative Instruments, Assets	19.5	48.9
Liability Derivatives	'	'
Fair Value of Derivative Instruments, Liabilities	-8.6	-1.6
Commodity Contracts [Member] | Current liabilities [Member]	'	'
Liability Derivatives	'	'
Fair Value of Derivative Instruments, Liabilities	-8.3	-0.1
Commodity Contracts [Member] | Long-term liabilities [Member]	'	'
Liability Derivatives	'	'
Fair Value of Derivative Instruments, Liabilities	-0.3	-1.5
Commodity Contracts [Member] | Current Asset [Member]	'	'
Asset Derivatives	'	'
Fair Value of Derivative Instruments, Assets	14.4	39.7
Commodity Contracts [Member] | Long-term assets [Member]	'	'
Asset Derivatives	'	'
Fair Value of Derivative Instruments, Assets	$5.10	$9.20

Effect_of_Derivative_Instrumen

Effect of Derivative Instruments in Statement of Operations (Detail) (Cash Flow Hedging [Member], USD $)	3 Months Ended				9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Derivative Instruments, Gain (Loss) [Line Items]	'		'		'		'
Derivative Instruments, Gain Recognized in Other Comprehensive Income (Loss), Effective Portion, Net, Total	($30.80)		($41.80)		($20.90)		$30.80
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net, Total	-2.1	[1]	10	[1]	13.8	[2]	18.4	[2]
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net, Total	-1.7		-1.8		-1.5		3.1
Commodity Contracts [Member]	'		'		'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'		'		'
Derivative Instruments, Gain Recognized in Other Comprehensive Income (Loss), Effective Portion, Net, Total	-30.8		-41.8		-20.9		30.8
Derivative (expense) income, net [Member]	'		'		'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'		'		'
Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net, Total	-1.7		-1.8		-1.5		3.1
Operating revenue - oil/gas production [Member]	'		'		'		'
Derivative Instruments, Gain (Loss) [Line Items]	'		'		'		'
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net, Total	($2.10)	[1]	$10	[1]	$13.80	[2]	$18.40	[2]
[1]	For the three months ended September 30, 2013, effective hedging contracts decreased oil revenue by $7.5 million and increased gas revenue by $5.4 million. For the three months ended September 30, 2012, effective hedging contracts increased oil revenue by $4.1 million and increased gas revenue by $5.9 million.
[2]	For the nine months ended September 30, 2013, effective hedging contracts increased oil revenue by $2.4 million and increased gas revenue by $11.4 million. For the nine months ended September 30, 2012, effective hedging contracts increased oil revenue by $1.1 million and increased gas revenue by $17.3 million.

Effect_of_Derivative_Instrumen1

Effect of Derivative Instruments in Statement of Operations (Parenthetical) (Detail) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Derivative Instruments And Hedging Activities Disclosure [Abstract]	'	'	'	'
Decrease/increase in oil revenue owing to effective hedging contracts	$7.50	$4.10	$2.40	$1.10
Decrease/increase in gas revenue owing to effective hedging contracts	$5.40	$5.90	$11.40	$17.30

Impact_of_Rights_of_Offset_Ass

Impact of Rights of Offset Associated with Recognized Assets and Liabilities (Detail) (USD $)	Sep. 30, 2013
In Millions, unless otherwise specified
Current Asset [Member]	'
Derivative Instruments And Hedging Activities [Line Items]	'
Fair Value of Derivative Instruments, Assets	$14.40
Long-term assets [Member]	'
Derivative Instruments And Hedging Activities [Line Items]	'
Fair Value of Derivative Instruments, Assets	5.1
Current liabilities [Member]	'
Derivative Instruments And Hedging Activities [Line Items]	'
Fair Value of Derivative Instruments, Liabilities	-8.3
Long-term liabilities [Member]	'
Derivative Instruments And Hedging Activities [Line Items]	'
Fair Value of Derivative Instruments, Liabilities	-0.3
Effects of Netting [Member] | Current Asset [Member]	'
Derivative Instruments And Hedging Activities [Line Items]	'
Fair Value of Derivative Instruments, Assets	-5
Effects of Netting [Member] | Long-term assets [Member]	'
Derivative Instruments And Hedging Activities [Line Items]	'
Fair Value of Derivative Instruments, Assets	-3.5
Effects of Netting [Member] | Current liabilities [Member]	'
Derivative Instruments And Hedging Activities [Line Items]	'
Fair Value of Derivative Instruments, Liabilities	8.2
Effects of Netting [Member] | Long-term liabilities [Member]	'
Derivative Instruments And Hedging Activities [Line Items]	'
Fair Value of Derivative Instruments, Liabilities	0.3
With Effects of Netting [Member] | Current Asset [Member]	'
Derivative Instruments And Hedging Activities [Line Items]	'
Fair Value of Derivative Instruments, Assets	9.4
With Effects of Netting [Member] | Long-term assets [Member]	'
Derivative Instruments And Hedging Activities [Line Items]	'
Fair Value of Derivative Instruments, Assets	1.6
With Effects of Netting [Member] | Current liabilities [Member]	'
Derivative Instruments And Hedging Activities [Line Items]	'
Fair Value of Derivative Instruments, Liabilities	-0.1
With Effects of Netting [Member] | Long-term liabilities [Member]	'
Derivative Instruments And Hedging Activities [Line Items]	'
Fair Value of Derivative Instruments, Liabilities	'

Hedging_Positions_Detail

Hedging Positions (Detail)	Sep. 30, 2013
	MMBTU
Natural Gas [Member] | 2013 Hedging Position One [Member]	'
Derivative [Line Items]	'
Daily Volume	10,000
Swap Price	4
Natural Gas [Member] | 2013 Hedging Position Two [Member]	'
Derivative [Line Items]	'
Daily Volume	10,000	[1]
Swap Price	4.05
Natural Gas [Member] | 2013 Hedging Position Three [Member]	'
Derivative [Line Items]	'
Daily Volume	20,000	[2]
Swap Price	4.45
Natural Gas [Member] | 2013 Hedging Position Four [Member]	'
Derivative [Line Items]	'
Daily Volume	10,000
Swap Price	5.27
Natural Gas [Member] | 2013 Hedging Position Five [Member]	'
Derivative [Line Items]	'
Daily Volume	10,000
Swap Price	5.32
Natural Gas [Member] | 2014 Hedging Position One [Member]	'
Derivative [Line Items]	'
Daily Volume	10,000
Swap Price	4
Natural Gas [Member] | 2014 Hedging Position Two [Member]	'
Derivative [Line Items]	'
Daily Volume	10,000
Swap Price	4.04
Natural Gas [Member] | 2014 Hedging Position Three [Member]	'
Derivative [Line Items]	'
Daily Volume	10,000
Swap Price	4.105
Natural Gas [Member] | 2014 Hedging Position Four [Member]	'
Derivative [Line Items]	'
Daily Volume	10,000
Swap Price	4.19
Natural Gas [Member] | 2014 Hedging Position Five [Member]	'
Derivative [Line Items]	'
Daily Volume	10,000
Swap Price	4.25
Natural Gas [Member] | 2014 Hedging Position Six [Member]	'
Derivative [Line Items]	'
Daily Volume	10,000
Swap Price	4.35
Natural Gas [Member] | 2015 Hedging Position One [Member]	'
Derivative [Line Items]	'
Daily Volume	10,000
Swap Price	4.005
Natural Gas [Member] | 2015 Hedging Position Two [Member]	'
Derivative [Line Items]	'
Daily Volume	10,000
Swap Price	4.22
Natural Gas [Member] | 2015 Hedging Position Three [Member]	'
Derivative [Line Items]	'
Daily Volume	10,000
Swap Price	4.255
Oil [Member] | 2013 Hedging Position One [Member]	'
Derivative [Line Items]	'
Daily Volume	2,000	[2]
Swap Price	92.35
Oil [Member] | 2013 Hedging Position Two [Member]	'
Derivative [Line Items]	'
Daily Volume	1,000
Swap Price	92.8
Oil [Member] | 2013 Hedging Position Three [Member]	'
Derivative [Line Items]	'
Daily Volume	2,000	[3]
Swap Price	94.05
Oil [Member] | 2013 Hedging Position Four [Member]	'
Derivative [Line Items]	'
Daily Volume	1,000
Swap Price	94.45
Oil [Member] | 2013 Hedging Position Five [Member]	'
Derivative [Line Items]	'
Daily Volume	1,000
Swap Price	94.6
Oil [Member] | 2013 Hedging Position Six [Member]	'
Derivative [Line Items]	'
Daily Volume	1,000
Swap Price	97.15
Oil [Member] | 2013 Hedging Position Seven [Member]	'
Derivative [Line Items]	'
Daily Volume	1,000
Swap Price	101.53
Oil [Member] | 2013 Hedging Position Eight [Member]	'
Derivative [Line Items]	'
Daily Volume	1,000
Swap Price	103
Oil [Member] | 2013 Hedging Position Nine [Member]	'
Derivative [Line Items]	'
Daily Volume	1,000
Swap Price	103.15
Oil [Member] | 2013 Hedging Position Ten [Member]	'
Derivative [Line Items]	'
Daily Volume	1,000
Swap Price	104.25
Oil [Member] | 2013 Hedging Position Eleven [Member]	'
Derivative [Line Items]	'
Daily Volume	1,000
Swap Price	104.47
Oil [Member] | 2013 Hedging Position Twelve [Member]	'
Derivative [Line Items]	'
Daily Volume	1,000
Swap Price	104.5
Oil [Member] | 2013 Hedging Position Thirteen [Member]	'
Derivative [Line Items]	'
Daily Volume	1,000	[4]
Swap Price	107.3
Oil [Member] | 2014 Hedging Position One [Member]	'
Derivative [Line Items]	'
Daily Volume	1,000
Swap Price	90.06
Oil [Member] | 2014 Hedging Position Two [Member]	'
Derivative [Line Items]	'
Daily Volume	1,000
Swap Price	92.25
Oil [Member] | 2014 Hedging Position Three [Member]	'
Derivative [Line Items]	'
Daily Volume	1,000
Swap Price	93.55
Oil [Member] | 2014 Hedging Position Four [Member]	'
Derivative [Line Items]	'
Daily Volume	1,000
Swap Price	94
Oil [Member] | 2014 Hedging Position Five [Member]	'
Derivative [Line Items]	'
Daily Volume	1,000
Swap Price	98
Oil [Member] | 2014 Hedging Position Six [Member]	'
Derivative [Line Items]	'
Daily Volume	1,000
Swap Price	98.3
Oil [Member] | 2014 Hedging Position Seven [Member]	'
Derivative [Line Items]	'
Daily Volume	2,000	[3]
Swap Price	98.85
Oil [Member] | 2014 Hedging Position Eight [Member]	'
Derivative [Line Items]	'
Daily Volume	1,000
Swap Price	99.65
Oil [Member] | 2014 Hedging Position Nine [Member]	'
Derivative [Line Items]	'
Daily Volume	1,000	[4]
Swap Price	103.3
Oil [Member] | 2015 Hedging Position One [Member]	'
Derivative [Line Items]	'
Daily Volume	1,000
Swap Price	90
[1]	April through December
[2]	July through December
[3]	January through June
[4]	Brent crude oil contract

LongTerm_Debt_Detail

Long-Term Debt (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'	'
Long-term debt	$923,745	$914,126
8.625% Senior Notes due 2017 [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	375,000	375,000
Senior Convertible Notes due 2017 [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	248,700	239,100
7.5% Senior Notes due 2022 [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	300,000	300,000
Bank Debt [Member]	'	'
Debt Instrument [Line Items]	'	'
Long-term debt	'	'

LongTerm_Debt_Additional_Infor

Long-Term Debt - Additional Information (Detail) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

1 Months Ended

3 Months Ended

9 Months Ended

9 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

9 Months Ended

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Dec. 31, 2012

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Nov. 05, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Mar. 06, 2012

Sep. 30, 2013

Dec. 31, 2012

Apr. 26, 2011

Sep. 30, 2013

Nov. 05, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Dec. 31, 2012

Letter of Credit [Member]

Letter of Credit [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Subsequent Event [Member]

Senior Convertible Notes due 2017 [Member]

Senior Convertible Notes due 2017 [Member]

Senior Convertible Notes due 2017 [Member]

Senior Convertible Notes due 2017 [Member]

Senior Convertible Notes due 2017 [Member]

Bank Debt [Member]

Bank Debt [Member]

Bank Debt [Member]

Bank Credit Facility [Member]

Bank Credit Facility [Member]

8.625 % Senior Notes Due 2017 [Member]

8.625 % Senior Notes Due 2017 [Member]

7.5% Senior Notes Due 2022 [Member]

7.5% Senior Notes Due 2022 [Member]

7.5% Senior Notes due 2022 [Member]

7.5% Senior Notes due 2022 [Member]

7.5% Senior Notes due 2022 [Member]

Letter of Credit [Member]

Subsequent Event [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Credit facility initial date

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

26-Apr-11

'

'

'

'

'

'

'

'

'

'

'

Redetermined base borrowing and credit facility

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$700,000,000

'

'

'

'

'

'

'

'

'

Maturity of new credit facility if note issue under 2004 indenture are retired on or before April 15, 2014

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

26-Apr-15

'

'

'

'

'

'

'

'

Initial bank and availability under facility

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

400,000,000

'

'

378,500,000

378,500,000

'

'

'

'

'

'

'

Outstanding borrowing under bank credit facility

'

'

'

'

'

21,500,000

21,500,000

'

'

21,500,000

'

'

'

'

'

'

'

'

0

0

'

'

'

'

'

'

'

Interest expense related to fees on bank credit facility and letters of credit

7,922,000

7,692,000

26,452,000

21,107,000

'

100,000

400,000

500,000

1,400,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Oil and gas reserve as proportion of discounted present value of future net cash flow, for mortgage

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

80.00%

'

'

'

'

'

'

'

'

'

'

'

Aggregate principal amount of Senior Subordinated Notes

'

'

'

'

'

'

'

'

'

'

'

'

'

'

300,000,000

'

'

'

'

'

'

'

'

'

'

'

'

Initial conversion rate of convertible note 2017

'

'

'

'

'

'

'

'

'

'

'

'

'An initial conversion rate of 23.4449 shares of our common stock per $1,000 principal amount of 2017 Convertible Notes

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Initial conversion rate of common stock

'

'

'

'

'

'

'

'

'

'

'

'

23.4449

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Principal amount of 2017 Convertible Notes

'

'

'

'

'

'

'

'

'

'

$1,000

$1,000

$1,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Initial conversion price of convertible note 2017

'

'

'

'

'

'

'

'

'

'

$42.65

$42.65

$42.65

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Closing share price

'

'

'

'

'

'

'

'

'

'

$32.43

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Payment for call option

'

'

'

'

'

'

'

'

'

'

'

'

70,800,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Anti-dilution adjustments for purchases of call option

'

'

'

'

'

'

'

'

'

'

'

'

7,033,470

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Strike price per share

'

'

'

'

'

'

'

'

'

'

'

$55.91

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Proceeds from sale of warrants

'

'

'

'

'

'

'

'

'

'

'

40,100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Liability component of convertible note

923,745,000

'

923,745,000

'

914,126,000

'

'

'

'

'

248,700,000

248,700,000

248,700,000

239,100,000

'

'

'

'

'

'

'

'

'

'

300,000,000

300,000,000

300,000,000

Interest cost related to amortization of discount

'

'

'

'

'

'

'

'

'

'

'

3,300,000

9,600,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of deferred financing cost

'

'

'

'

'

'

'

'

'

'

'

300,000

900,000

'

'

'

'

'

'

'

400,000

1,200,000

200,000

500,000

'

'

'

Interest expense related to contractual interest coupon of convertible notes

'

'

'

'

'

'

'

'

'

'

'

$1,300,000

$3,900,000

'

'

'

'

'

'

'

$8,100,000

$24,300,000

'

'

$5,600,000

$16,800,000

'

Changes_in_Asset_Retirement_Ob

Changes in Asset Retirement Obligations (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Asset Retirement Obligation Disclosure [Abstract]	'	'	'	'
Asset retirement obligations as of the beginning of the period, including current portion	'	'	$488,300,000	'
Liabilities incurred	'	'	16,500,000	'
Liabilities settled	'	'	-61,200,000	'
Accretion expense	8,431,000	8,405,000	25,012,000	24,926,000
Asset retirement obligations as of the end of the period, including current portion	$468,600,000	'	$468,600,000	'

Acquisitions_Additional_Inform

Acquisitions - Additional Information (Detail) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Jun. 18, 2012
Business Acquisition [Line Items]	'	'
Fair value of Land and Building at the time of Acquisition	$8.50	'
Purchase Consideration	8.5	'
Cash consideration transferred	'	$26.40
Block Deep Water Pompano Field Mississippi Canyon [Member]	'	'
Business Acquisition [Line Items]	'	'
Percentage of working interest acquired	'	25.00%
Mississippi Canyon Block 29 [Member]	'	'
Business Acquisition [Line Items]	'	'
Percentage of working interest acquired	'	14.00%
Mississippi Canyon Block 72 [Member]	'	'
Business Acquisition [Line Items]	'	'
Percentage of working interest acquired	'	10.00%

Allocation_of_Recorded_Value_o

Allocation of Recorded Value of Net Assets Acquired in Transaction (Detail) (USD $)	Jun. 18, 2012
In Millions, unless otherwise specified
Business Combinations [Abstract]	'
Proved oil and gas properties	$39.20
Unevaluated oil and gas properties	1.6
Asset retirement obligations	-14.4
Total fair value of net assets	$26.40

Assets_and_Liabilities_Measure

Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Marketable securities	$8	$13.50
Assets, Fair Value, Total	27.5	62.4
Derivative Liabilities, Fair Value	'	-1.6
Liabilities, Fair Value, Total	-8.6	-1.6
Hedging contracts [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Assets, Fair Value	19.5	48.9
Derivative Liabilities, Fair Value	-8.6	'
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Marketable securities	8	13.5
Assets, Fair Value, Total	8	13.5
Derivative Liabilities, Fair Value	'	'
Liabilities, Fair Value, Total	'	'
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Hedging contracts [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Assets, Fair Value	'	'
Derivative Liabilities, Fair Value	'	'
Significant Other Observable Inputs (Level 2) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Marketable securities	'	'
Assets, Fair Value, Total	19.5	48.9
Derivative Liabilities, Fair Value	'	-1.6
Liabilities, Fair Value, Total	-8.6	-1.6
Significant Other Observable Inputs (Level 2) [Member] | Hedging contracts [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Assets, Fair Value	19.5	48.9
Derivative Liabilities, Fair Value	-8.6	'
Significant Unobservable Inputs (Level 3) [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Marketable securities	'	'
Assets, Fair Value, Total	'	'
Derivative Liabilities, Fair Value	'	'
Liabilities, Fair Value, Total	'	'
Significant Unobservable Inputs (Level 3) [Member] | Hedging contracts [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Assets, Fair Value	'	'
Derivative Liabilities, Fair Value	'	'

Fair_Value_Measurements_Additi

Fair Value Measurements - Additional Information (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified
8.625 % Senior Notes Due 2017 [Member]	'	'
Debt Instrument [Line Items]	'	'
Long term debt, Fair Value	$397.50	$401.30
Convertible Notes Due 2017 [Member]	'	'
Debt Instrument [Line Items]	'	'
Liability component of convertible note	287.4	249.6
7.5% Senior Notes due 2022 [Member]	'	'
Debt Instrument [Line Items]	'	'
Liability component of convertible note	$317.30	$314.30

Schedule_of_Changes_In_Accumul

Schedule of Changes In Accumulated Other Comprehensive Income Loss (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Jun. 18, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'	'
Beginning balance, net of tax	$24,500,000	'	$28,833,000	'	'
Other comprehensive income (loss) before reclassifications:	'	'	'	'	'
Change in fair value of derivatives	-30,800,000	'	-20,900,000	'	'
Foreign currency translations	300,000	'	-200,000	'	'
Income tax effect	11,100,000	'	7,600,000	'	'
Net of tax	-19,400,000	'	-13,500,000	'	'
Amounts reclassified from accumulated other comprehensive income:	'	'	'	'	'
Net of tax	1,300,000	'	-8,900,000	'	'
Other comprehensive income (loss), net of tax	-18,100,000	'	-22,400,000	'	'
Ending balance, net of tax	6,413,000	'	6,413,000	'	'
Cash Flow Hedges [Member]	'	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'	'
Beginning balance, net of tax	25,000,000	'	28,833,000	21,900,000	63,000,000
Other comprehensive income (loss) before reclassifications:	'	'	'	'	'
Change in fair value of derivatives	-30,800,000	-41,800,000	-20,900,000	30,800,000	'
Income tax effect	11,100,000	15,000,000	7,600,000	-11,100,000	'
Net of tax	-19,700,000	-26,800,000	-13,300,000	19,700,000	'
Amounts reclassified from accumulated other comprehensive income:	'	'	'	'	'
Net of tax	1,300,000	-6,400,000	-8,900,000	-11,800,000	'
Other comprehensive income (loss), net of tax	-18,400,000	-33,200,000	-22,200,000	7,900,000	'
Ending balance, net of tax	6,600,000	29,800,000	6,600,000	29,800,000	63,000,000
Foreign Currency Items [Member]	'	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'	'
Beginning balance, net of tax	-500,000	'	'	'	'
Other comprehensive income (loss) before reclassifications:	'	'	'	'	'
Foreign currency translations	300,000	'	-200,000	'	'
Net of tax	300,000	'	-200,000	'	'
Amounts reclassified from accumulated other comprehensive income:	'	'	'	'	'
Other comprehensive income (loss), net of tax	300,000	'	-200,000	'	'
Ending balance, net of tax	200,000	'	200,000	'	'
Reclassification out of Accumulated Other Comprehensive Income [Member]	'	'	'	'	'
Amounts reclassified from accumulated other comprehensive income:	'	'	'	'	'
Operating revenue: oil/gas production	2,100,000	'	-13,800,000	'	'
Income tax effect	-800,000	'	4,900,000	'	'
Reclassification out of Accumulated Other Comprehensive Income [Member] | Cash Flow Hedges [Member]	'	'	'	'	'
Amounts reclassified from accumulated other comprehensive income:	'	'	'	'	'
Operating revenue: oil/gas production	2,100,000	-10,000,000	-13,800,000	-18,400,000	'
Income tax effect	-800,000	3,600,000	4,900,000	6,600,000	'
Reclassification out of Accumulated Other Comprehensive Income [Member] | Foreign Currency Items [Member]	'	'	'	'	'
Amounts reclassified from accumulated other comprehensive income:	'	'	'	'	'
Operating revenue: oil/gas production	'	'	'	'	'
Income tax effect	'	'	'	'	'

Investment_in_Oil_and_Gas_Prop1

Investment in Oil and Gas Properties - Additional Information (Detail) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]	'	'
Capital expenditures related to oil and gas property investments	$576,395	$447,795
Canada	'	'
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]	'	'
Capital expenditures related to oil and gas property investments	$9,700	'

Commitments_and_Contingencies_

Commitments and Contingencies - Additional Information (Detail) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013
Commitments And Contingencies Disclosure [Abstract]	'
Approximate asserted claims plus accrued interest assessed by Louisiana Department of Revenue	$30.50
Additional estimated assessments including interest by Louisiana Department of Revenue	3.4
Minimum potential range contingency loss	0
Maximum potential range contingency loss	$33.90

Subsequent_Events_Additional_I

Subsequent Events - Additional Information (Detail) (Subsequent Event [Member], USD $)	1 Months Ended
In Millions, unless otherwise specified	Oct. 31, 2013
Subsequent Event [Member]	'
Subsequent Event [Line Items]	'
Cash consideration received on sale of interest in Weeks Island field	$46

Condensed_Consolidating_Balanc

Condensed Consolidating Balance Sheet (Detail) (USD $)	Sep. 30, 2013		Jun. 30, 2013	Dec. 31, 2012		Sep. 30, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Current assets:	'		'	'		'	'
Cash and cash equivalents	$243,075		'	$279,526		$176,186	$38,451
Accounts receivable	189,565		'	167,288		'	'
Fair value of hedging contracts	14,423		'	39,655		'	'
Current income tax receivable	10,893		'	10,027		'	'
Deferred taxes	26,350	[1]	'	15,514	[1]	'	'
Inventory	3,843		'	4,207		'	'
Other current assets	1,439		'	3,626		'	'
Total current assets	489,588		'	519,843		'	'
Oil and gas properties, full cost method: Proved	7,589,153		'	7,244,466		'	'
Less: accumulated DD&A	-5,762,937		'	-5,510,166		'	'
Net proved oil and gas properties	1,826,216		'	1,734,300		'	'
Unevaluated	576,395		'	447,795		'	'
Other property and equipment, net	23,965		'	22,115		'	'
Fair value of hedging contracts	5,114		'	9,199		'	'
Other assets, net	49,148		'	43,179		'	'
Total assets	2,970,426		'	2,776,431		'	'
Current liabilities:	'		'	'		'	'
Accounts payable to vendors	104,486		'	94,361		'	'
Undistributed oil and gas proceeds	42,913		'	23,414		'	'
Accrued interest	14,272		'	18,546		'	'
Fair value of hedging contracts	8,261		'	149		'	'
Asset retirement obligations	60,938		'	66,260		'	'
Other current liabilities	21,680		'	16,765		'	'
Total current liabilities	252,550		'	219,495		'	'
Long-term debt	923,745		'	914,126		'	'
Deferred taxes	387,033	[1]	'	310,830	[1]	'	'
Asset retirement obligations	407,712		'	422,042		'	'
Fair value of hedging contracts	360		'	1,530		'	'
Other long-term liabilities	26,463		'	36,275		'	'
Total liabilities	1,997,863		'	1,904,298		'	'
Commitments and contingencies	'		'	'		'	'
Stockholders' equity:	'		'	'		'	'
Common stock	488		'	484		'	'
Treasury stock	-860		'	-860		'	'
Additional paid-in capital	1,393,439		'	1,386,475		'	'
Accumulated deficit	-426,917		'	-542,799		'	'
Accumulated other comprehensive income	6,413		24,500	28,833		'	'
Total stockholders' equity	972,563		'	872,133		'	'
Total liabilities and stockholders' equity	2,970,426		'	2,776,431		'	'
Parent [Member]	'		'	'		'	'
Current assets:	'		'	'		'	'
Cash and cash equivalents	191,193		'	228,398		155,089	37,389
Accounts receivable	83,310		'	59,213		'	'
Current income tax receivable	10,893		'	10,027		'	'
Deferred taxes	6,631	[1]	'	5,947	[1]	'	'
Inventory	3,560		'	3,924		'	'
Other current assets	1,439		'	3,626		'	'
Total current assets	297,026		'	311,135		'	'
Oil and gas properties, full cost method: Proved	1,211,964		'	1,004,808		'	'
Less: accumulated DD&A	-429,380		'	-370,111		'	'
Net proved oil and gas properties	782,584		'	634,697		'	'
Unevaluated	274,986		'	254,757		'	'
Other property and equipment, net	23,965		'	22,115		'	'
Other assets, net	44,324		'	41,679		'	'
Investment in subsidiary	896,798		'	736,331		'	'
Total assets	2,319,683		'	2,000,714		'	'
Current liabilities:	'		'	'		'	'
Accounts payable to vendors	289,204		'	74,503		'	'
Undistributed oil and gas proceeds	39,141		'	21,841		'	'
Accrued interest	14,272		'	18,546		'	'
Other current liabilities	17,242		'	16,765		'	'
Total current liabilities	359,859		'	131,655		'	'
Long-term debt	923,745		'	914,126		'	'
Deferred taxes	31,295	[1]	'	47,758	[1]	'	'
Asset retirement obligations	5,758		'	5,479		'	'
Other long-term liabilities	26,463		'	29,563		'	'
Total liabilities	1,347,120		'	1,128,581		'	'
Commitments and contingencies	'		'	'		'	'
Stockholders' equity:	'		'	'		'	'
Common stock	488		'	484		'	'
Treasury stock	-860		'	-860		'	'
Additional paid-in capital	1,393,439		'	1,386,475		'	'
Accumulated deficit	-426,917		'	-542,799		'	'
Accumulated other comprehensive income	6,413		'	28,833		'	'
Total stockholders' equity	972,563		'	872,133		'	'
Total liabilities and stockholders' equity	2,319,683		'	2,000,714		'	'
Guarantor Subsidiary [Member]	'		'	'		'	'
Current assets:	'		'	'		'	'
Cash and cash equivalents	51,242		'	51,128		21,097	926
Accounts receivable	313,610		'	108,075		'	'
Fair value of hedging contracts	14,423		'	39,655		'	'
Deferred taxes	19,719	[1]	'	9,567	[1]	'	'
Inventory	283		'	283		'	'
Total current assets	399,277		'	208,708		'	'
Oil and gas properties, full cost method: Proved	6,377,189		'	6,239,658		'	'
Less: accumulated DD&A	-5,333,557		'	-5,140,055		'	'
Net proved oil and gas properties	1,043,632		'	1,099,603		'	'
Unevaluated	291,750		'	193,038		'	'
Fair value of hedging contracts	5,114		'	9,199		'	'
Other assets, net	1,349		'	1,500		'	'
Total assets	1,741,122		'	1,512,048		'	'
Current liabilities:	'		'	'		'	'
Accounts payable to vendors	22,576		'	19,858		'	'
Undistributed oil and gas proceeds	3,772		'	1,573		'	'
Fair value of hedging contracts	8,261		'	149		'	'
Asset retirement obligations	60,938		'	66,260		'	'
Other current liabilities	4,438		'	'		'	'
Total current liabilities	99,985		'	87,840		'	'
Deferred taxes	355,738	[1]	'	263,072	[1]	'	'
Asset retirement obligations	401,954		'	416,563		'	'
Fair value of hedging contracts	360		'	1,530		'	'
Other long-term liabilities	'		'	6,712		'	'
Total liabilities	858,037		'	775,717		'	'
Commitments and contingencies	'		'	'		'	'
Stockholders' equity:	'		'	'		'	'
Additional paid-in capital	1,496,509		'	1,496,510		'	'
Accumulated deficit	-620,093		'	-789,012		'	'
Accumulated other comprehensive income	6,669		'	28,833		'	'
Total stockholders' equity	883,085		'	736,331		'	'
Total liabilities and stockholders' equity	1,741,122		'	1,512,048		'	'
Non-Guarantor Subsidiaries [Member]	'		'	'		'	'
Current assets:	'		'	'		'	'
Cash and cash equivalents	640		'	'		'	136
Total current assets	640		'	'		'	'
Unevaluated	9,659		'	'		'	'
Other assets, net	3,475		'	'		'	'
Investment in subsidiary	13,116		'	'		'	'
Total assets	26,890		'	'		'	'
Current liabilities:	'		'	'		'	'
Accounts payable to vendors	61		'	'		'	'
Total current liabilities	61		'	'		'	'
Total liabilities	61		'	'		'	'
Commitments and contingencies	'		'	'		'	'
Stockholders' equity:	'		'	'		'	'
Additional paid-in capital	27,404		'	'		'	'
Accumulated deficit	-64		'	'		'	'
Accumulated other comprehensive income	-511		'	'		'	'
Total stockholders' equity	26,829		'	'		'	'
Total liabilities and stockholders' equity	26,890		'	'		'	'
Eliminations [Member]	'		'	'		'	'
Current assets:	'		'	'		'	'
Accounts receivable	-207,355		'	'		'	'
Total current assets	-207,355		'	'		'	'
Investment in subsidiary	-909,914		'	-736,331		'	'
Total assets	-1,117,269		'	-736,331		'	'
Current liabilities:	'		'	'		'	'
Accounts payable to vendors	-207,355		'	'		'	'
Total current liabilities	-207,355		'	'		'	'
Total liabilities	-207,355		'	'		'	'
Commitments and contingencies	'		'	'		'	'
Stockholders' equity:	'		'	'		'	'
Additional paid-in capital	-1,523,913		'	-1,496,510		'	'
Accumulated deficit	620,157		'	789,012		'	'
Accumulated other comprehensive income	-6,158		'	-28,833		'	'
Total stockholders' equity	-909,914		'	-736,331		'	'
Total liabilities and stockholders' equity	($1,117,269)		'	($736,331)		'	'
[1]	Deferred income taxes have been allocated to the Guarantor Subsidiary where related oil and gas properties reside.

Condensed_Consolidating_Statem

Condensed Consolidating Statement of Operations (Detail) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Operating revenue:	'	'	'	'
Oil production	$186,608	$180,806	$558,031	$564,745
Gas production	52,728	34,003	137,382	91,006
Natural gas liquids production	16,476	11,910	36,854	35,228
Other operational income	873	678	2,659	2,520
Derivative income, net	'	'	'	3,119
Total operating revenue	256,685	227,397	734,926	696,618
Operating expenses:	'	'	'	'
Lease operating expenses	53,986	60,995	157,547	157,030
Transportation, processing and gathering expenses	13,081	6,762	27,374	15,911
Production taxes	5,224	1,842	11,404	7,578
Depreciation, depletion, amortization	92,853	89,274	255,497	260,982
Accretion expense	8,431	8,405	25,012	24,926
Salaries, general and administrative	14,201	13,673	43,351	40,521
Incentive compensation expense	4,566	67	8,047	3,907
Other operational expenses	237	82	382	195
Derivative expense, net	1,684	1,812	1,537	'
Total operating expenses	194,263	182,912	530,151	511,050
Income (loss) from operations	62,422	44,485	204,775	185,568
Other (income) expenses:	'	'	'	'
Interest expense	7,922	7,692	26,452	21,107
Interest income	-1,311	-117	-1,543	-227
Other income	-782	-443	-2,190	-1,229
(Income) loss from investment in subsidiaries	'	'	'	'
Total other (income) expenses	5,829	7,132	22,719	19,651
Income (loss) before taxes	56,593	37,353	182,056	165,917
Provision (benefit) for income taxes:	'	'	'	'
Current	-88	595	-10,827	1,164
Deferred	20,579	13,099	77,001	59,573
Total income taxes	20,491	13,694	66,174	60,737
Net income	36,102	23,659	115,882	105,180
Comprehensive income (loss)	17,985	-9,507	93,462	113,151
Parent [Member]	'	'	'	'
Operating revenue:	'	'	'	'
Oil production	6,904	7,682	20,625	20,729
Gas production	19,971	9,197	47,240	20,693
Natural gas liquids production	9,224	5,436	17,901	11,010
Other operational income	711	568	2,150	2,024
Total operating revenue	36,810	22,883	87,916	54,456
Operating expenses:	'	'	'	'
Lease operating expenses	3,895	5,886	9,611	17,108
Transportation, processing and gathering expenses	10,072	4,163	17,853	8,361
Production taxes	1,773	684	3,960	2,354
Depreciation, depletion, amortization	26,728	19,336	62,007	45,884
Accretion expense	93	138	279	423
Salaries, general and administrative	14,202	13,672	43,300	40,516
Incentive compensation expense	4,566	67	8,047	3,907
Other operational expenses	194	61	295	150
Derivative expense, net	'	'	'	'
Total operating expenses	61,523	44,007	145,352	118,703
Income (loss) from operations	-24,713	-21,124	-57,436	-64,247
Other (income) expenses:	'	'	'	'
Interest expense	7,922	7,671	26,431	21,189
Interest income	-1,234	-112	-1,384	-216
Other income	-230	-98	-671	-121
(Income) loss from investment in subsidiaries	-56,166	-42,200	-168,887	-160,650
Total other (income) expenses	-49,708	-34,739	-144,511	-139,798
Income (loss) before taxes	24,995	13,615	87,075	75,551
Provision (benefit) for income taxes:	'	'	'	'
Current	-88	595	-10,827	1,164
Deferred	-11,019	-10,639	-17,980	-30,793
Total income taxes	-11,107	-10,044	-28,807	-29,629
Net income	36,102	23,659	115,882	105,180
Comprehensive income (loss)	17,985	-9,507	93,462	113,151
Guarantor Subsidiary [Member]	'	'	'	'
Operating revenue:	'	'	'	'
Oil production	179,704	173,124	537,406	544,016
Gas production	32,757	24,806	90,142	70,313
Natural gas liquids production	7,252	6,474	18,953	24,218
Other operational income	162	-1	509	139
Derivative income, net	'	'	'	3,119
Total operating revenue	219,875	204,403	647,010	641,805
Operating expenses:	'	'	'	'
Lease operating expenses	50,091	55,107	147,936	139,937
Transportation, processing and gathering expenses	3,009	2,599	9,521	7,550
Production taxes	3,451	1,158	7,444	5,224
Depreciation, depletion, amortization	66,125	69,939	193,490	214,908
Accretion expense	8,338	8,181	24,733	24,246
Salaries, general and administrative	'	1	4	5
Incentive compensation expense	'	'	'	'
Other operational expenses	43	21	87	45
Derivative expense, net	1,684	1,812	1,537	'
Total operating expenses	132,741	138,818	384,752	391,915
Income (loss) from operations	87,134	65,585	262,258	249,890
Other (income) expenses:	'	'	'	'
Interest expense	'	21	21	-82
Interest income	-69	-5	-144	-11
Other income	-552	-345	-1,519	-1,108
(Income) loss from investment in subsidiaries	'	-24	'	75
Total other (income) expenses	-621	-353	-1,642	-1,126
Income (loss) before taxes	87,755	65,938	263,900	251,016
Provision (benefit) for income taxes:	'	'	'	'
Current	'	'	'	'
Deferred	31,598	23,738	94,981	90,366
Total income taxes	31,598	23,738	94,981	90,366
Net income	56,157	42,200	168,919	160,650
Comprehensive income (loss)	56,157	42,200	168,919	160,650
Non-Guarantor Subsidiaries [Member]	'	'	'	'
Operating revenue:	'	'	'	'
Other operational income	'	111	'	357
Total operating revenue	'	111	'	357
Operating expenses:	'	'	'	'
Lease operating expenses	'	2	'	-15
Depreciation, depletion, amortization	'	-1	'	190
Accretion expense	'	86	'	257
Salaries, general and administrative	-1	'	47	'
Total operating expenses	-1	87	47	432
Income (loss) from operations	1	24	-47	-75
Other (income) expenses:	'	'	'	'
Interest income	-8	'	-15	'
(Income) loss from investment in subsidiaries	-7	'	32	'
Total other (income) expenses	-15	'	17	'
Income (loss) before taxes	16	24	-64	-75
Provision (benefit) for income taxes:	'	'	'	'
Net income	16	24	-64	-75
Comprehensive income (loss)	16	24	-64	-75
Eliminations [Member]	'	'	'	'
Other (income) expenses:	'	'	'	'
(Income) loss from investment in subsidiaries	56,173	42,224	168,855	160,575
Total other (income) expenses	56,173	42,224	168,855	160,575
Income (loss) before taxes	-56,173	-42,224	-168,855	-160,575
Provision (benefit) for income taxes:	'	'	'	'
Net income	-56,173	-42,224	-168,855	-160,575
Comprehensive income (loss)	($56,173)	($42,224)	($168,855)	($160,575)

Condensed_Consolidating_Statem1

Condensed Consolidating Statement of Cash Flows (Detail) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:	'	'
Net income (loss)	$115,882	$105,180
Adjustments to reconcile net income (loss) to net cash provided by operating activities:	'	'
Depreciation, depletion and amortization	255,497	260,982
Accretion expense	25,012	24,926
Deferred income tax provision (benefit)	77,001	59,573
Settlement of asset retirement obligations	-61,178	-47,211
Non-cash stock compensation expense	7,583	6,800
Excess tax benefits	-156	-882
Non-cash derivative expense	1,626	-584
Non-cash interest expense	12,384	9,068
Other non-cash expense	'	16
Change in current income taxes	-704	-3,240
(Increase) decrease in accounts receivable	-22,277	-15,832
(Increase) decrease in other current assets	2,187	-2,456
Decrease in inventory	158	136
Increase (decrease) in accounts payable	8,035	6,116
Increase (decrease) in other current liabilities	20,251	-24,301
Other	-1,791	-4,378
Net cash provided by (used in) operating activities	439,510	373,913
Cash flows from investing activities:	'	'
Investment in oil and gas properties	-472,304	-445,311
Proceeds from sale of oil and gas properties, net of expenses	6,300	403
Sale of fixed assets	'	134
Investment in fixed and other assets	-3,830	-3,998
Change in restricted funds	-2,394	'
Net cash used in investing activities	-472,228	-448,772
Cash flows from financing activities:	'	'
Proceeds from bank borrowings	'	25,000
Deferred financing costs	-11	'
Repayments of bank borrowings	'	-70,000
Proceeds from issuance of senior convertible notes	'	300,000
Deferred financing costs of senior convertible notes	'	-8,855
Proceeds from sold warrants	'	40,170
Payments for purchased call options	'	-70,830
Excess tax benefits	156	882
Net payments for share-based compensation	-3,733	-3,773
Net cash (used in) provided by financing activities	-3,588	212,594
Effect of exchange rate changes on cash	-145	'
Net change in cash and cash equivalents	-36,451	137,735
Cash and cash equivalents, beginning of period	279,526	38,451
Cash and cash equivalents, end of period	243,075	176,186
Parent [Member]	'	'
Cash flows from operating activities:	'	'
Net income (loss)	115,882	105,180
Adjustments to reconcile net income (loss) to net cash provided by operating activities:	'	'
Depreciation, depletion and amortization	62,007	45,884
Accretion expense	279	423
Deferred income tax provision (benefit)	-17,980	-30,793
Non-cash stock compensation expense	7,583	6,800
Excess tax benefits	-156	-882
Non-cash interest expense	12,384	9,068
Other non-cash expense	'	16
Non-cash (income) loss from investment in subsidiaries	-168,887	'
Change in current income taxes	-704	-3,240
Change in intercompany receivables/payables	207,267	207,166
(Increase) decrease in accounts receivable	-24,053	-9,229
(Increase) decrease in other current assets	2,187	-2,456
Decrease in inventory	158	136
Increase (decrease) in accounts payable	2,610	5,733
Increase (decrease) in other current liabilities	13,613	-20,441
Other	499	-163,921
Net cash provided by (used in) operating activities	212,689	149,444
Cash flows from investing activities:	'	'
Investment in oil and gas properties	-234,776	-240,877
Proceeds from sale of oil and gas properties, net of expenses	6,300	403
Sale of fixed assets	'	134
Investment in fixed and other assets	-3,830	-3,998
Investment in subsidiaries	-14,000	'
Net cash used in investing activities	-246,306	-244,338
Cash flows from financing activities:	'	'
Proceeds from bank borrowings	'	25,000
Deferred financing costs	-11	'
Repayments of bank borrowings	'	-70,000
Proceeds from issuance of senior convertible notes	'	300,000
Deferred financing costs of senior convertible notes	'	-8,855
Proceeds from sold warrants	'	40,170
Payments for purchased call options	'	-70,830
Excess tax benefits	156	882
Net payments for share-based compensation	-3,733	-3,773
Net cash (used in) provided by financing activities	-3,588	212,594
Net change in cash and cash equivalents	-37,205	117,700
Cash and cash equivalents, beginning of period	228,398	37,389
Cash and cash equivalents, end of period	191,193	155,089
Guarantor Subsidiary [Member]	'	'
Cash flows from operating activities:	'	'
Net income (loss)	168,919	160,650
Adjustments to reconcile net income (loss) to net cash provided by operating activities:	'	'
Depreciation, depletion and amortization	193,490	214,908
Accretion expense	24,733	24,246
Deferred income tax provision (benefit)	94,981	90,366
Settlement of asset retirement obligations	-61,178	-47,211
Non-cash derivative expense	1,626	-584
Change in intercompany receivables/payables	-207,311	-206,669
(Increase) decrease in accounts receivable	1,776	-6,631
Increase (decrease) in accounts payable	5,425	422
Increase (decrease) in other current liabilities	6,638	-3,860
Other	-2,290	-1,032
Net cash provided by (used in) operating activities	226,809	224,605
Cash flows from investing activities:	'	'
Investment in oil and gas properties	-226,695	-204,434
Net cash used in investing activities	-226,695	-204,434
Cash flows from financing activities:	'	'
Net change in cash and cash equivalents	114	20,171
Cash and cash equivalents, beginning of period	51,128	926
Cash and cash equivalents, end of period	51,242	21,097
Non-Guarantor Subsidiaries [Member]	'	'
Cash flows from operating activities:	'	'
Net income (loss)	-64	-75
Adjustments to reconcile net income (loss) to net cash provided by operating activities:	'	'
Depreciation, depletion and amortization	'	190
Accretion expense	'	257
Non-cash (income) loss from investment in subsidiaries	32	'
Change in intercompany receivables/payables	44	-497
(Increase) decrease in accounts receivable	'	28
Increase (decrease) in accounts payable	'	-39
Net cash provided by (used in) operating activities	12	-136
Cash flows from investing activities:	'	'
Investment in oil and gas properties	-10,833	'
Change in restricted funds	-2,394	'
Investment in subsidiaries	-13,404	'
Net cash used in investing activities	-26,631	'
Cash flows from financing activities:	'	'
Equity proceeds from parent	27,404	'
Net cash (used in) provided by financing activities	27,404	'
Effect of exchange rate changes on cash	-145	'
Net change in cash and cash equivalents	640	-136
Cash and cash equivalents, beginning of period	'	136
Cash and cash equivalents, end of period	640	'
Eliminations [Member]	'	'
Cash flows from operating activities:	'	'
Net income (loss)	-168,855	-160,575
Adjustments to reconcile net income (loss) to net cash provided by operating activities:	'	'
Non-cash (income) loss from investment in subsidiaries	168,855	'
Other	'	160,575
Cash flows from investing activities:	'	'
Investment in subsidiaries	27,404	'
Net cash used in investing activities	27,404	'
Cash flows from financing activities:	'	'
Equity proceeds from parent	-27,404	'
Net cash (used in) provided by financing activities	($27,404)	'