Bill Barrett (BBG) 10-K 27 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
	Dec. 31, 2014	Jan. 27, 2015	Jun. 30, 2014
Document Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	BBG
Entity Registrant Name	BILL BARRETT CORPORATION
Entity Central Index Key	1172139
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		49,551,397
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$1,321,646,601

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$165,904	$54,595
Accounts receivable, net of allowance for doubtful accounts	112,209	97,586
Derivative assets	145,226	173
Prepayments and other current assets	2,766	4,893
Total current assets	426,105	157,247
Property and equipment - at cost, successful efforts method for oil and gas properties:
Proved oil and gas properties	2,009,292	2,863,923
Unproved oil and gas properties, excluded from amortization	148,834	246,433
Oil and gas properties held for sale, net of amortization and impairment	9,234	0
Furniture, equipment and other	39,963	41,726
Property, plant and equipment, gross	2,207,323	3,152,082
Accumulated depreciation, depletion, amortization and impairment	-454,202	-949,586
Total property and equipment, net	1,753,121	2,202,496
Derivative assets	49,750	2,539
Deferred financing costs and other noncurrent assets	15,508	19,231
Total	2,244,484	2,381,513
Current liabilities:
Accounts payable and accrued liabilities	126,252	115,928
Amounts payable to oil and gas property owners	19,187	26,778
Production taxes payable	38,060	39,235
Derivative liabilities	0	5,988
Deferred income taxes	55,418	199
Current portion of long-term debt	25,770	4,591
Total current liabilities	264,687	192,719
Long-term debt	803,222	979,082
Asset retirement obligations	21,592	39,200
Liabilities associated with assets held for sale	146	0
Deferred income taxes	122,350	161,326
Derivatives and other noncurrent liabilities	2,999	3,468
Stockholders’ equity:
Common stock, $0.001 par value; authorized 150,000,000 shares; 49,526,637 and 49,152,448 shares issued and outstanding at December 31, 2014 and 2013, respectively, with 1,407,141 and 1,340,060 shares subject to restrictions, respectively	48	48
Additional paid-in capital	913,619	904,261
Retained earnings	115,821	100,740
Treasury stock, at cost: zero shares at December 31, 2014 and 2013	0	0
Accumulated other comprehensive income	0	669
Total stockholders’ equity	1,029,488	1,005,718
Total	$2,244,484	$2,381,513

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	49,526,637	49,152,448
Common stock, shares outstanding	49,526,637	49,152,448
Common stock, shares subject to restrictions	1,407,141	1,340,060
Treasury stock, shares	0	0

CONSOLIDATED_STATEMENTS_OF_OPE

CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating and Other Revenues:
Oil, gas and NGL production	$464,137	$565,555	$700,639
Other	8,154	2,538	-444
Total operating and other revenues	472,291	568,093	700,195
Operating Expenses:
Lease operating expense	60,308	70,217	72,734
Gathering, transportation and processing expense	35,437	67,269	106,548
Production tax expense	31,333	27,172	25,513
Exploration expense	453	337	8,814
Impairment, dry hole costs and abandonment expense	46,881	238,398	67,869
Loss on divestitures	100,407	0	0
Depreciation, depletion and amortization	235,805	279,775	326,842
Unused commitments	4,434	0	0
General and administrative expense	53,361	64,902	68,666
Total operating expenses	568,419	748,070	676,986
Operating Income (Loss)	-96,128	-179,977	23,209
Other Income and Expense:
Interest and other income	1,294	1,646	155
Interest expense	-69,623	-88,507	-95,506
Commodity derivative gain (loss)	197,447	-23,068	72,759
Gain (loss) on extinguishment of debt	0	-21,460	1,601
Total other income and expense	129,118	-131,389	-20,991
Income (Loss) before Income Taxes	32,990	-311,366	2,218
Provision for (Benefit from) Income Taxes	17,909	-118,633	1,636
Net income (loss)	$15,081	($192,733)	$582
Net Income (Loss) Per Common Share, Basic	$0.31	($4.06)	$0.01
Net Income (Loss) Per Common Share, Diluted	$0.31	($4.06)	$0.01
Weighted Average Common Shares Outstanding, Basic	48,010,730	47,496,857	47,194,668
Weighted Average Common Shares Outstanding, Diluted	48,435,725	47,496,857	47,353,951

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Comprehensive Income [Abstract]
Net Income (Loss)	$15,081	($192,733)	$582
Other Comprehensive Loss, net of tax:
Effect of derivative financial instruments	-669	-4,663	-50,712
Other comprehensive loss	-669	-4,663	-50,712
Comprehensive Income (Loss)	$14,412	($197,396)	($50,130)

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Activities:
Net Income (Loss)	$15,081	($192,733)	$582
Adjustments to reconcile to net cash provided by operations:
Depreciation, depletion and amortization	235,805	279,775	326,842
Deferred income taxes	16,644	-117,050	-185
Impairment, dry hole costs and abandonment expense	46,881	238,398	67,869
Commodity derivative (gain) loss	-197,447	23,068	-72,759
Settlements of commodity derivatives	-1,888	5,315	42,305
Stock compensation and other non-cash charges	11,352	16,027	18,328
Amortization of debt discounts and deferred financing costs	4,264	5,604	8,425
(Gain) loss on extinguishment of debt	0	21,460	-1,601
(Gain) loss on sale of properties	100,407	-130	4,279
APIC pool for excess tax benefits related to share-based compensation	0	1,259	-32
Change in operating assets and liabilities:
Accounts receivable	32,163	14,294	-10,511
Prepayments and other assets	1,643	1,394	1,293
Accounts payable, accrued and other liabilities	5,119	-35,600	2,589
Amounts payable to oil and gas property owners	-7,132	9,997	3,988
Production taxes payable	-1,175	-5,813	-2,976
Net cash provided by operating activities	261,717	265,265	388,436
Investing Activities:
Additions to oil and gas properties, including acquisitions	-580,943	-445,479	-958,654
Additions of furniture, equipment and other	-3,658	-2,254	-7,231
Proceeds from sale of properties and other investing activities	555,296	310,704	328,888
Net cash used in investing activities	-29,305	-137,029	-636,997
Financing Activities:
Proceeds from debt	165,000	420,000	875,826
Principal and redemption premium payments on debt	-283,546	-576,422	-595,386
Proceeds from stock option exercises	126	6,385	673
APIC pool for excess tax benefits related to share-based compensation	0	-1,259	0
Deferred financing costs and other	-2,683	-1,790	-10,438
Net cash provided by (used in) financing activities	-121,103	-153,086	270,675
Increase (Decrease) in Cash and Cash Equivalents	111,309	-24,850	22,114
Beginning Cash and Cash Equivalents	54,595	79,445	57,331
Ending Cash and Cash Equivalents	$165,904	$54,595	$79,445

CONSOLIDATED_STATEMENTS_OF_STO

CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (USD $)	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income [Member]
In Thousands, unless otherwise specified
Balance at Dec. 31, 2011	$1,218,838	$47	$869,856	$292,891	$0	$56,044
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of options, restricted stock activity and shares exchanged for exercise and tax withholding	-1,840	0	673		-2,513
APIC pool for excess tax benefits related to share-based compensation	32		32
Stock-based compensation	16,874		16,874
Retirement of treasury stock	0		-2,513		2,513
Settlement of convertible notes	999		-999
Net Income (Loss)	582			582
Effect of derivative financial instruments, net of taxes	-50,712					-50,712
Balance at Dec. 31, 2012	1,182,775	47	883,923	293,473	0	5,332
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of options, restricted stock activity and shares exchanged for exercise and tax withholding	4,607	1	6,384		-1,778
APIC pool for excess tax benefits related to share-based compensation	-1,259		-1,259
Stock-based compensation	16,991		16,991
Retirement of treasury stock	0		-1,778		1,778
Net Income (Loss)	-192,733			-192,733
Effect of derivative financial instruments, net of taxes	-4,663					-4,663
Balance at Dec. 31, 2013	1,005,718	48	904,261	100,740	0	669
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of options, restricted stock activity and shares exchanged for exercise and tax withholding	-2,558	0	126		-2,684
Stock-based compensation	11,916		11,916
Retirement of treasury stock	0		-2,684		2,684
Net Income (Loss)	15,081			15,081
Effect of derivative financial instruments, net of taxes	-669					-669
Balance at Dec. 31, 2014	$1,029,488	$48	$913,619	$115,821	$0	$0

CONSOLIDATED_STATEMENTS_OF_STO1

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Stockholders' Equity [Abstract]
Effect of derivative financial instruments, taxes	$410	$2,802	$30,458

Organization

Organization	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization	Organization
	Bill Barrett Corporation, a Delaware corporation, together with its wholly-owned subsidiaries (collectively, the "Company") is an independent oil and gas company engaged in the exploration, development and production of oil, natural gas and NGLs. Since its inception in January 2002, the Company has conducted its activities principally in the Rocky Mountain region of the United States.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies
	Basis of Presentation. The accompanying Consolidated Financial Statements include the accounts of the Company. These statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP"). All intercompany accounts and transactions have been eliminated in consolidation.
	Use of Estimates. In the course of preparing the Company’s financial statements in accordance with GAAP, management makes various assumptions, judgments and estimates to determine the reported amount of assets, liabilities, revenues and expenses and in the disclosure of commitments and contingencies. Changes in these assumptions, judgments and estimates will occur as a result of the passage of time and the occurrence of future events and, accordingly, actual results could differ from amounts initially established.
	Areas requiring the use of assumptions, judgments and estimates relate to the expected cash settlement of the Company’s 5% Convertible Senior Notes due 2028 ("Convertible Notes") in computing diluted earnings per share, volumes of oil, natural gas and NGL reserves used in calculating depreciation, depletion and amortization ("DD&A"), the amount of expected future cash flows used in determining possible impairments of oil and gas properties and the amount of future capital costs used in these calculations. Assumptions, judgments and estimates also are required in determining asset retirement obligations, the timing of dry hole costs, impairments of proved and unproved properties, valuing deferred tax assets and estimating fair values of derivative instruments and stock-based payment awards.
	Accounts Receivable. Accounts receivable is comprised of the following:
		As of December 31,
		2014				2013
		(in thousands)
	Accrued oil, gas and NGL sales	$	35,099			$	67,583
	Due from joint interest owners	27,937				23,507
	Other (1)	49,187				6,517
	Allowance for doubtful accounts	(14		)		(21		)
	Total accounts receivable	$	112,209			$	97,586
	-1	Other includes a receivable of $47.6 million (including $4.7 million due to another industry partner) related to a settlement agreement with the Department of Interior ("DOI") resulting in the cancellation of certain Cottonwood Gulch natural gas leases during the three months ended December 31, 2014.
	Cash and Cash Equivalents. The Company considers all highly liquid investments with a remaining maturity of three months or less when purchased to be cash equivalents.
	Oil and Gas Properties. The Company’s oil, gas and NGL exploration and production activities are accounted for using the successful efforts method. Under this method, all property acquisition costs and costs of exploratory and development wells are capitalized when incurred, pending determination of whether the well has found proved reserves. If an exploratory well does not find proved reserves, the costs of drilling the well are charged to expense and included within cash flows from investing activities in the Consolidated Statements of Cash Flows. If an exploratory well does find proved reserves, the costs remain capitalized and are included within additions to oil and gas properties within cash flows from investing activities in the Consolidated Statements of Cash Flows when paid. The costs of development wells are capitalized whether proved reserves are added or not. Oil and gas lease acquisition costs are also capitalized. Upon sale or retirement of depreciable or depletable property, the cost and related accumulated DD&A are eliminated from the accounts and the resulting gain or loss is recognized.
	Other exploration costs, including certain geological and geophysical expenses and delay rentals for oil and gas leases, are charged to expense as incurred. The sale of a partial interest in a proved property is accounted for as a cost recovery and no gain or loss is recognized as long as this treatment does not significantly affect the unit-of-production amortization rate. Maintenance and repairs are charged to expense, and renewals and betterments are capitalized to the appropriate property and equipment accounts.
	Unproved oil and gas property costs are transferred to proved oil and gas properties if the properties are subsequently determined to be productive or are assigned proved reserves. Proceeds from sales of partial interests in unproved leases are accounted for as a recovery of cost without recognizing any gain until all costs are recovered. Unproved oil and gas properties are assessed periodically for impairment based on remaining lease terms, drilling results, reservoir performance, commodity price outlooks, future plans to develop acreage and other relevant matters.
	Materials and supplies consist primarily of tubular goods and well equipment to be used in future drilling operations or repair operations and are carried at the lower of cost or market value, on a first-in, first-out basis.
	The following table sets forth the net capitalized costs and associated accumulated DD&A and non-cash impairments relating to the Company’s oil, natural gas and NGL producing activities:
		As of December 31,
		2014				2013
		(in thousands)
	Proved properties	$	390,482			$	485,427
	Wells and related equipment and facilities	1,537,370				2,192,754
	Support equipment and facilities	68,371				177,224
	Materials and supplies	13,069				8,518
	Total proved oil and gas properties	$	2,009,292			$	2,863,923
	Unproved properties	78,898				189,759
	Wells and facilities in progress	69,936				56,674
	Total unproved oil and gas properties, excluded from amortization	$	148,834			$	246,433
	Assets held for sale	9,234				—
	Accumulated depreciation, depletion, amortization and impairment	(427,954		)		(926,173		)
	Total oil and gas properties, net	$	1,739,406			$	2,184,183
	All exploratory wells are evaluated for economic viability within one year of well completion. Exploratory wells that discover potentially economic reserves in areas where a major capital expenditure would be required before production could begin, and where the economic viability of that major capital expenditure depends upon the successful completion of further exploratory work in the area, remain capitalized if the well finds a sufficient quantity of reserves to justify its completion as a producing well and the Company is making sufficient progress assessing the reserves and the economic and operating viability of the project. As of December 31, 2014 and 2013, there were no exploratory well costs that had been capitalized for a period greater than one year since the completion of drilling.
	The Company reviews proved oil and gas properties on a field-by-field basis for impairment on a quarterly basis or whenever events and circumstances indicate that a decline in the recoverability of their carrying value may have occurred. The Company estimates the expected undiscounted future cash flows of its oil and gas properties and compares such undiscounted future cash flows to the carrying amount of the oil and gas properties to determine if the carrying amount is recoverable. If the carrying value of a property exceeds the undiscounted future cash flows, the Company will impair the carrying value to fair value based on an analysis of quantitative and qualitative factors. The Company has no guarantee that the undiscounted future cash flows analysis of its proved property represents the applicable market value. The factors used to determine fair value include, but are not limited to, recent sales prices of comparable properties, the present value of future revenues, net of estimated operating and development costs using estimates of reserves, future commodity pricing, future production estimates, anticipated capital expenditures and various discount rates commensurate with the risk and current market conditions associated with realizing the expected cash flows projected.
	The Company recognized non-cash impairment charges, which were included within impairment, dry hole costs and abandonment expense in the Consolidated Statements of Operations, as follows:
		Year Ended December 31,
		2014				2013				2012
		(in thousands)
	Non-cash impairment of proved oil and gas properties	$	15,761		(1)	$	206,953		(3)	$	—
	Non-cash impairment of unproved oil and gas properties	24,082			(2)	19,598			(3)	37,348		(4)
	Non-cash impairment of inventory	340				—				—
	Dry hole costs	101				1,124				21,012
	Abandonment expense	6,597				10,723				9,509
	Total non-cash impairment, dry hole costs and abandonment expense	$	46,881			$	238,398			$	67,869
	-1	As a result of the Powder River Oil Divestiture (see Note 4), the carrying values of the remaining properties were analyzed relative to their estimated fair market value. As a result, the Company recognized impairment of $14.8 million. These properties were classified as held for sale as of December 31, 2014. The remaining impairment of $1.0 million related to the West Tavaputs Divestiture (see Note 4) based upon a true up of previously estimated carrying value.
	-2	As a result of unfavorable drilling and completion results in the Paradox Basin, the Company recognized an impairment of $11.6 million related to unproved oil and gas properties. In addition, the Company recognized an impairment of $6.1 million related to certain unproved oil and gas properties in the Uinta Basin as a result of no future plans to evaluate certain acreage positions. The Company recognized an impairment of $6.4 million to unproved oil and gas properties as the result of the Powder River Oil Divestiture discussed in (1) above.
	-3	As a result of an analysis of remaining carrying values relative to fair market values resulting from the West Tavaputs Divestiture (see Note 4), $207.0 million and $2.5 million of proved and unproved property impairment, respectively, was incurred during the year ended December 31, 2013. As a result of no future plans to evaluate remaining acreage and estimated market value below carrying value within various exploration projects, an additional $17.1 million of unproved property impairment was incurred during the year ended December 31, 2013.
	-4	As a result of unfavorable natural gas exploratory results, no future plans to evaluate remaining acreage and estimated market value below our carrying value within exploration projects, $37.3 million of unproved property impairment was incurred during the year ended December 31, 2012.
	The provision for DD&A of oil and gas properties is calculated on a field-by-field basis using the unit-of-production method. Natural gas and NGLs are converted to an oil equivalent, Boe, at the standard rate of six Mcf to one Boe and forty-two gallons to one Boe, respectively. Estimated future dismantlement, restoration and abandonment costs are taken into consideration by this calculation.
	Accounts Payable and Accrued Liabilities. Accounts payable and accrued liabilities are comprised of the following:
		As of December 31,
		2014				2013
		(in thousands)
	Accrued drilling, completion and facility costs	$	68,124			$	54,750
	Accrued lease operating, gathering, transportation and processing expenses	12,526				17,317
	Accrued general and administrative expenses	8,482				14,605
	Accrued interest payable	14,284				14,860
	Accrued payables for property sales	16,296				2,905
	Trade payables and other	6,540				11,491
	Total accounts payable and accrued liabilities	$	126,252			$	115,928
	Environmental Liabilities. Environmental expenditures that relate to an existing condition caused by past operations and that do not contribute to current or future revenue generation are expensed. Environmental liabilities are accrued when environmental assessments and/or clean-ups are probable, and the costs can be reasonably estimated.
	Revenue Recognition. Oil, gas and NGL revenues are recognized when production is sold to a purchaser at a fixed or determinable price, when delivery has occurred and title has transferred, and collectability of the revenue is reasonably assured. The Company uses the sales method to account for gas and NGL imbalances. Under this method, revenues are recorded on the basis of gas and NGLs actually sold by the Company. In addition, the Company records revenues for its share of gas and NGLs sold by other owners that cannot be volumetrically balanced in the future due to insufficient remaining reserves. The Company also reduces revenues for other owners' gas and NGLs sold by the Company that cannot be volumetrically balanced in the future due to insufficient remaining reserves. The Company's remaining over- and under- produced gas and NGLs balancing positions are taken into account in determining the Company's proved oil, gas and NGL reserves. Imbalances at December 31, 2014 and 2013 were not material.
Derivative Instruments and Hedging Activities. The Company periodically uses derivative financial instruments to achieve a more predictable cash flow from its oil, natural gas and NGL sales by reducing its exposure to price fluctuations. Derivative instruments are recorded at fair market value and are included in the Consolidated Balance Sheets as assets or liabilities.
Income Taxes. Income taxes are provided for the tax effects of transactions reported in the financial statements and consist of taxes currently payable plus deferred income taxes related to certain income and expenses recognized in different periods for financial and income tax reporting purposes. Deferred income tax assets and liabilities represent the future tax return consequences of those differences, which will either be taxable or deductible when assets are recovered or liabilities are settled. Deferred income taxes also include tax credits and net operating losses that are available to offset future income taxes. Deferred income taxes are measured by applying currently enacted tax rates.
The Company accounts for uncertainty in income taxes for tax positions taken or expected to be taken in a tax return. Only tax positions that meet the more-likely-than-not recognition threshold are recognized.
Earnings/Loss Per Share. Basic net income (loss) per common share is calculated by dividing net income (loss) attributable to common stock by the weighted average number of common shares outstanding during each period. Diluted net income (loss) per common share is calculated by dividing net income (loss) attributable to common stock by the weighted average number of common shares outstanding and other dilutive securities. Potentially dilutive securities for the diluted net income per common share calculations consist of nonvested equity shares of common stock, in-the-money outstanding stock options to purchase the Company’s common stock and shares into which the Convertible Notes are convertible. No potential common shares are included in the computation of any diluted per share amount when a net loss exists, as was the case for the year ended December 31, 2013.
In satisfaction of its obligation upon conversion of the Convertible Notes, the Company may elect to deliver, at its option, cash, shares of its common stock or a combination of cash and shares of its common stock. As of December 31, 2014, the Company expected to settle the remaining Convertible Notes in cash. Therefore, the treasury stock method was used to measure the potentially dilutive impact of shares associated with that remaining conversion feature. The Company has the right at any time with at least 30 days’ notice to call the Convertible Notes and the holders have the right to require the Company to purchase the notes on March 20, 2015, March 20, 2018 and March 20, 2023. The Convertible Notes have not been dilutive since their issuance in March 2008 and, therefore, did not impact the diluted net income per common share calculation for the years ended December 31, 2014 and 2012. The diluted net income per common share excludes the anti-dilutive effect of 1,406,938 and 3,162,436 stock options and nonvested equity shares of common stock for the years ended December 31, 2014 and 2012, respectively.
The following table sets forth the calculation of basic and diluted net income (loss) per share:
	Year Ended December 31,
	2014				2013				2012
	(in thousands, except per share amounts)
Net income (loss)	$	15,081			$	(192,733	)		$	582
Basic weighted-average common shares outstanding in period	48,011				47,497				47,195
Add dilutive effects of stock options and nonvested equity shares of common stock	425				—				159
Diluted weighted-average common shares outstanding in period	48,436				47,497				47,354
Basic net income (loss) per common share	$	0.31			$	(4.06	)		$	0.01
Diluted net income (loss) per common share	$	0.31			$	(4.06	)		$	0.01
Industry Segment and Geographic Information. The Company operates in one industry segment, which is the development and production of crude oil, natural gas and NGLs, and all of the Company’s operations are conducted in the continental United States. Consequently, the Company currently reports as a single industry segment.
New Accounting Pronouncements. In August 2014, the FASB issued ASU 2014-15, Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern. The objective of this update is to provide guidance in GAAP about management's responsibility to evaluate whether there is substantial doubt about an entity's ability to continue as a going concern and to provide related footnote disclosures. ASU 2014-15 is effective for the annual period ending after December 15, 2016, and for annual periods and interim periods thereafter. The standard will be adopted prospectively.
In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers. The objective of this update is to clarify the principles for recognizing revenue and to develop a common revenue standard. ASU 2014-09 is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. The Company is currently evaluating the potential impact that the adoption will have on the Company’s disclosures and financial statements.
Reclassifications. Certain amounts in the prior period Consolidated Balance Sheets have been reclassified to conform to the current period's presentation. During the year ended December 31, 2014, we changed the presentation of unproved oil and gas properties to present unproved oil and gas properties, net of impairment. Impairment of unproved oil and gas properties was included in accumulated depreciation, depletion, amortization and impairment in the prior period. The total property and equipment subtotal was not affected by this reclassification nor were any other financial statements.

Supplemental_Disclosures_of_Ca

Supplemental Disclosures of Cash Flow Information	12 Months Ended
	Dec. 31, 2014
Supplemental Cash Flow Elements [Abstract]
Supplemental Disclosures of Cash Flow Information	Supplemental Disclosures of Cash Flow Information
	Supplemental cash flow information is as follows:
		Year Ended December 31,
		2014			2013			2012
		(in thousands)
	Cash paid for interest, net of amount capitalized	$	65,935		$	94,205		$	83,718
	Cash paid for income taxes	1			1,163			10
	Supplemental disclosures of non-cash investing and financing activities:
	Accrued receivables - oil and gas properties (1)	42,872			—			—
	Accrued liabilities - oil and gas properties	72,297			75,340			49,598
	Change in asset retirement obligations, net of disposals	(22,740		)	(6,996		)	(25,236		)
	Retirement of treasury stock	2,684			1,778			2,513
	Fair value of properties exchanged in non-cash transactions	77,078			—			—
	Transfer of lease financing obligation	36,075			45,190			—
	-1	Includes a receivable of $42.9 million related to a settlement agreement with the Department of Interior ("DOI") resulting in the cancellation of certain Cottonwood Gulch natural gas leases in 2014.

Divestitures_and_Assets_Held_f

Divestitures and Assets Held for Sale	12 Months Ended
	Dec. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]
Divestitures	Divestitures and Assets Held for Sale
	Divestitures. During the year ended December 31, 2014, the Company completed the sale or exchange of the majority of its Powder River Basin assets (the "Powder River Oil Divestiture") in four separate transactions with effective dates of April 1, 2014 and closing dates during the three months ended September 30, 2014. The sale resulted in net cash proceeds of $30.0 million, after initial closing adjustments. Three transactions involved the cumulative sale of 17,497 net mineral acres. The fourth transaction involved an exchange of 29,015 net mineral acres in the Powder River Basin for 7,856 net mineral acres within the southern block of the Company’s operated Northeast Wattenberg area of the Denver-Julesburg Basin, valued at $71.0 million. Assets sold or exchanged as part of the overall Powder River Oil Divestiture included $86.2 million in proved and $40.6 million in unproved oil and gas properties, net of accumulated depreciation, depletion, amortization and impairment of $33.1 million and $1.3 million in asset retirement obligations. A loss on sale of $24.5 million related to these transactions is included within operating expenses in the Consolidated Statements of Operations. The divestiture proceeds are subject to various purchase price adjustments incurred in the normal course of business and will be finalized in 2015.
	On September 30, 2014, the Company completed the sale of its Gibson Gulch natural gas program in the Piceance Basin (the "Piceance Divestiture") with an effective date of July 1, 2014. The Company received $498.7 million in cash proceeds, after initial closing estimates. In addition to the cash proceeds, the Company recognized non-cash proceeds of $22.4 million related to the relief of the Company's asset retirement obligation and $36.1 million related to the transfer of the Company's lease financing obligation described in Note 5 (the "Lease Financing Obligation"). A loss on sale of $79.5 million related to this transaction is included within operating expenses in the Consolidated Statements of Operations. The divestiture proceeds are subject to various purchase price adjustments incurred in the normal course of business and will be finalized in 2015. The carrying amounts by major asset class within the disposal group for the Piceance Divestiture are summarized below (in thousands):
	Assets:
	Proved properties	$	1,320,745
	Furniture, equipment and other	4,907
	Accumulated depreciation, depletion, amortization and impairment	(688,864		)
	Total assets	$	636,788
	Liabilities:
	Asset retirement obligation	$	22,448
	Lease financing obligation	36,075
	Other liabilities	84
	Total liabilities	$	58,607
	Net assets	$	578,181
	On December 10, 2013, the Company completed the sale of its West Tavaputs natural gas assets in the Uinta Basin (the "West Tavaputs Divestiture"). The Company received $308.7 million in cash proceeds, after closing adjustments. The divestiture proceeds were subject to various purchase price adjustments incurred in the normal course of business and were finalized during 2014. The Company recognized an impairment loss of $1.0 million during the year ended December 31, 2014 related to these assets based upon a true up of previously estimated carrying value. An initial impairment loss of $209.5 million related to these assets was recognized during the year ended December 31, 2013.
	On December 31, 2012, the Company completed the sale of natural gas assets including 100% of its Wind River Basin, 100% of the Powder River Basin coalbed methane assets, and a non-operating working interest in its Gibson Gulch-Piceance Basin development property (the "2012 Divestiture"). The Company received $325.3 million in cash proceeds and recognized a $4.5 million pre-tax loss included in other operating revenues for the year ended December 31, 2012. Due to final post-closing adjustments, the Company recognized an additional $3.1 million pre-tax loss included in other operating revenues for the year ended December 31, 2013.
	Assets Held for Sale. The Company began marketing its remaining Powder River Basin assets, including 19,492 net mineral acres, during 2014. Therefore, the related assets and liabilities were classified as held for sale in the Consolidated Balance Sheet as of December 31, 2014. Upon the classification as held for sale, the assets were analyzed relative to their fair market values. The Company recognized proved and unproved property impairment of $14.8 million and $6.4 million, respectively, during the year ended December 31, 2014.

LongTerm_Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt
	The Company’s outstanding debt is summarized below:
			As of December 31, 2014								As of December 31, 2013
		Maturity Date	Principal			Unamortized			Carrying		Principal		Unamortized		Carrying
						Discount			Amount				Discount		Amount
			(in thousands)
	Amended Credit Facility (1)	October 31, 2016	$	—		$	—		$	—	$	115,000	$	—	$	115,000
	Convertible Notes (2)	March 15, 2028 (3)	25,344			—			25,344		25,344		—		25,344
	7.625% Senior Notes (4)	October 1, 2019	400,000			—			400,000		400,000		—		400,000
	7.0% Senior Notes (5)	October 15, 2022	400,000			—			400,000		400,000		—		400,000
	Lease Financing Obligation (6)	August 10, 2020	3,648			—			3,648		43,329		—		43,329
	Total Debt		$	828,992		$	—		$	828,992	$	983,673	$	—	$	983,673
	Less: Current Portion of Long-Term Debt (7)(8)		25,770			—			25,770		4,591		—		4,591
	Total Long-Term Debt		$	803,222		$	—		$	803,222	$	979,082	$	—	$	979,082
	-1	The recorded value of the Amended Credit Facility approximates its fair value due to its floating rate structure.
	-2	The aggregate estimated fair value of the Convertible Notes was approximately $25.1 million as of December 31, 2014 and 2013, based on reported market trades of these instruments.
	-3	The Company has the right at any time, with at least 30 days’ notice, to call the Convertible Notes, and the holders have the right to require the Company to purchase the notes on each of March 20, 2015, March 20, 2018 and March 20, 2023.
	-4	The aggregate estimated fair value of the 7.625% Senior Notes was approximately $359.8 million and $430.2 million as of December 31, 2014 and 2013, respectively, based on reported market trades of these instruments.
	-5	The aggregate estimated fair value of the 7.0% Senior Notes was approximately $366.0 million and $417.0 million as of December 31, 2014 and 2013, respectively, based on reported market trades of these instruments.
	-6	The aggregate estimated fair value of the Lease Financing Obligation was approximately $3.5 million and $41.7 million as of December 31, 2014 and 2013, respectively. The decrease in estimated fair value is primarily related to the sale of equipment in the Piceance Divestiture. As there is no active public market for the Lease Financing Obligation, the aggregate estimated fair value was based on market-based parameters of comparable term secured financing instruments.
	-7	The current portion of long-term debt as of December 31, 2014 includes the current portion of the Lease Financing Obligation and the principal amount of the Convertible Notes. The Company classified the Convertible Notes as a current obligation as of December 31, 2014 as the holders may require us to purchase their Convertible Notes for cash on March 20, 2015.
	-8	The current portion of long-term debt as of December 31, 2013 includes the current portion of the Lease Financing Obligation.
	Amended Credit Facility
	The Company’s Amended Credit Facility has a maturity date of October 31, 2016 and current commitments and borrowing base of $375.0 million. As of December 31, 2014, the Company had no amounts outstanding under the Amended Credit Facility. As credit support for future payment under a contractual obligation, a $26.0 million letter of credit has been issued under the Amended Credit Facility, which reduced the current available borrowing capacity of the Amended Credit Facility as of December 31, 2014 to $349.0 million.
	Interest rates are LIBOR plus applicable margins of 1.5% to 2.5% or ABR plus 0.5% to 1.5% and the commitment fee is between 0.375% to 0.5% based on borrowing base utilization. The average annual interest rates incurred on the Amended Credit Facility were 1.9% and 2.0% for the years ended December 31, 2014 and 2013, respectively.
	The borrowing base is required to be re-determined twice per year. On September 30, 2014, the borrowing base was reduced to $375.0 million based on June 30, 2014 reserves as adjusted for the Piceance and Powder River Oil Divestitures and the Company's hedge position. Future semi-annual borrowing bases will be computed based on proved oil, natural gas and NGL reserves, hedge positions and estimated future cash flows from those reserves, as well as any other outstanding debt of the Company.
	The Amended Credit Facility also contains certain financial covenants. The Company is currently in compliance with all financial covenants and has complied with all financial covenants since issuance.
	5% Convertible Senior Notes Due 2028
	On March 12, 2008, the Company issued $172.5 million aggregate principal amount of Convertible Notes. On March 20, 2012, $147.2 million of the outstanding principal amount, or approximately 85% of the outstanding Convertible Notes, were put to the Company and redeemed by the Company at par. The Company settled the notes in cash. After the redemption, $25.3 million aggregate principal amount of the Convertible Notes was outstanding. The Convertible Notes mature on March 15, 2028, unless earlier converted, redeemed or purchased by the Company. The Convertible Notes are senior unsecured obligations and rank equal in right of payment to all of the Company’s existing and future senior unsecured indebtedness, are senior in right of payment to all of the Company’s future subordinated indebtedness, and are effectively subordinated to all of the Company’s secured indebtedness with respect to the collateral securing such indebtedness. The Convertible Notes are structurally subordinated to all present and future secured and unsecured debt and other obligations of the Company’s subsidiaries. The Convertible Notes are fully and unconditionally guaranteed by the subsidiaries that guarantee the Company’s indebtedness under the Amended Credit Facility, the 7.625% Senior Notes and the 7.0% Senior Notes.
	The Convertible Notes bear interest at a rate of 5% per annum, payable semi-annually in arrears on March 15 and September 15 of each year. Holders of the remaining Convertible Notes may require the Company to purchase all or a portion of their Convertible Notes for cash on each of March 20, 2015, March 20, 2018 and March 20, 2023 at a purchase price equal to 100% of the principal amount of the Convertible Notes to be repurchased, plus accrued and unpaid interest, if any, up to but excluding the applicable purchase date. The Company has the right, with at least 30 days’ notice, to call the Convertible Notes. The Company classified the Convertible Notes as a current obligation on the Consolidated Balance Sheets as of December 31, 2014 as the holders may require us to purchase their Convertible Notes for cash on March 20, 2015.
	7.625% Senior Notes Due 2019
	On September 27, 2011, the Company issued $400.0 million in principal amount of 7.625% Senior Notes due 2019 at par. The 7.625% Senior Notes mature on October 1, 2019. Interest is payable in arrears semi-annually on April 1 and October 1 beginning April 1, 2012. The 7.625% Senior Notes are senior unsecured obligations of the Company and rank equal in right of payment with all of the Company’s other existing and future senior unsecured indebtedness, including the Company’s Convertible Notes and 7.0% Senior Notes. The 7.625% Senior Notes are redeemable at the Company’s option at a redemption price of 103.813% of the principal amount of the notes on October 1, 2015. The 7.625% Senior Notes are fully and unconditionally guaranteed by the subsidiaries that guarantee the Company’s indebtedness under the Amended Credit Facility, the Convertible Notes and the 7.0% Senior Notes. The 7.625% Senior Notes include certain covenants that limit the Company’s ability to incur additional indebtedness, make restricted payments, create liens or sell assets and that prohibit the Company from paying dividends. The Company is currently in compliance with all financial covenants and has complied with all financial covenants since issuance.
	7.0% Senior Notes Due 2022
	On March 12, 2012, the Company issued $400.0 million in aggregate principal amount of 7.0% Senior Notes due 2022 at par. The 7.0% Senior Notes mature on October 15, 2022. Interest is payable in arrears semi-annually on April 15 and October 15 of each year. The 7.0% Senior Notes are senior unsecured obligations and rank equal in right of payment with all of the Company’s other existing and future senior unsecured indebtedness, including the Company’s Convertible Notes and 7.625% Senior Notes. The 7.0% Senior Notes are redeemable at the Company's option on October 15, 2017 at a redemption price of 103.5% of the principal amount of the notes. The 7.0% Senior Notes are fully and unconditionally guaranteed by the subsidiaries that guarantee the Company’s indebtedness under the Amended Credit Facility, the Convertible Notes and the 7.625% Senior Notes. The 7.0% Senior Notes include certain covenants that limit the Company’s ability to incur additional indebtedness, make restricted payments, create liens or sell assets and that prohibit the Company from paying dividends. The Company is currently in compliance with all financial covenants and has complied with all financial covenants since issuance.
	Lease Financing Obligation Due 2020
	On July 23, 2012, the Company entered into the Lease Financing Obligation, whereby the Company received $100.8 million through the sale and subsequent leaseback of existing compressors and related facilities owned by the Company. The Lease Financing Obligation expires on August 10, 2020, and the Company has the option to purchase the equipment at the end of the lease term for the then current fair market value. The Lease Financing Obligation also contains an early buyout option where the Company may purchase the equipment on February 10, 2019. The lease payments related to the equipment are recognized as principal and interest expense based on a weighted average implicit interest rate of 3.3%. See Note 13 for discussion of aggregate minimum future lease payments. As the result of the disposition of equipment in the West Tavaputs Divestiture and the Piceance Divestiture, the Company's remaining Lease Financing Obligation has been reduced to $3.6 million as of December 31, 2014 and the early buyout option is reduced to $1.8 million.
	The following table summarizes, for the periods indicated, the cash or accrued portion of interest expense related to the Amended Credit Facility, 9.875% Senior Notes that were redeemed in full on July 15, 2013, Convertible Notes, 7.625% Senior Notes, 7.0% Senior Notes and the Lease Financing Obligation along with the non-cash portion resulting from the amortization of the debt discount and transaction costs through interest expense:
		As of December 31,
		2014			2013			2012
		(in thousands)
	Amended Credit Facility (1)
	Cash interest	$	4,837		$	6,802		$	5,652
	Non-cash interest	2,342			2,342			2,342
	9.875% Senior Notes (2)
	Cash interest	$	—		$	13,373		$	24,688
	Non-cash interest	—			1,361			2,571
	Convertible Notes (3)
	Cash interest	$	1,264		$	1,267		$	2,909
	Non-cash interest	5			6			1,771
	7.625% Senior Notes (4)
	Cash interest	$	30,500		$	30,500		$	30,500
	Non-cash interest	1,090			1,070			1,066
	7.0% Senior Notes (5)
	Cash interest	$	28,000		$	28,000		$	22,400
	Non-cash interest	814			795			659
	Lease Financing Obligation (6)
	Cash interest	$	638		$	2,852		$	1,353
	Non-cash interest	12			30			15
	-1	Cash interest includes amounts related to interest and commitment fees paid on the Amended Credit Facility and participation and fronting fees paid on the letter of credit.
	-2	The stated interest rate for the 9.875% Senior Notes was 9.875% per annum with an effective interest rate of 11.2% per annum. The Company redeemed the 9.875% Senior Notes in full on July 15, 2013.
	-3	The stated interest rate for the Convertible Notes is 5% per annum. The effective interest rate of the Convertible Notes includes amortization of the debt discount, which represented the fair value of the equity conversion feature at the time of issue. The stated interest rate of 5% on the Convertible Notes is the effective interest rate of the $25.3 million remaining principal balance, as the related debt discount was fully amortized as of March 31, 2012.
	-4	The stated interest rate for the 7.625% Senior Notes is 7.625% per annum with an effective interest rate of 8.0% per annum.
	-5	The stated interest rate for the 7.0% Senior Notes is 7.0% per annum with an effective interest rate of 7.2% per annum.
	-6	The effective interest rate for the Lease Financing Obligation is 3.3% per annum. The decrease in cash interest from $2.9 million to $0.6 million for the years ended December 31, 2013 and 2014, respectively, is due to the West Tavaputs and Piceance Divestitures.

Asset_Retirement_Obligations

Asset Retirement Obligations	12 Months Ended
	Dec. 31, 2014
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligations	Asset Retirement Obligations
	A reconciliation of the Company’s asset retirement obligations for the year ended December 31, 2014, 2013 and 2012 is as follows:
		Year Ended December 31,
		2014			2013			2012
		(in thousands)
	Beginning of period	$	43,005		$	47,616		$	69,302
	Liabilities incurred	4,027			2,359			4,046
	Liabilities settled	(6,283		)	(1,096		)	(871		)
	Disposition of properties	(23,722		)	(13,543		)	(33,560		)
	Accretion expense	2,587			3,481			4,421
	Revisions to estimate	3,238			4,188			4,278
	End of period	$	22,852		$	43,005		$	47,616
	Less: Liabilities associated with properties held for sale	146			—			—
	Less: Current asset retirement obligations	1,114			3,805			1,566
	Long-term asset retirement obligations	$	21,592		$	39,200		$	46,050

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements
	Assets and Liabilities Measured on a Recurring Basis
	The Company’s financial instruments, including cash and cash equivalents, accounts and notes receivable and accounts payable are carried at cost, which approximates fair value due to the short-term maturity of these instruments. The recorded value of the Amended Credit Facility, as discussed in Note 5, approximates its fair value due to its floating rate structure based on the LIBOR spread and the Company's borrowing base utilization.
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). The Company utilizes a mid-market pricing convention (the mid-point price between bid and ask prices) for valuation as a practical expedient for assigning fair value. The Company uses market data or assumptions that market participants would use in pricing the asset or liability, including assumptions about risk. These inputs can be readily observable, market corroborated or generally unobservable. The Company primarily applies the market and income approaches for recurring fair value measurements and utilizes the best available information. Given the Company’s historical market transactions, its markets and instruments are fairly liquid. Therefore, the Company has been able to classify fair value balances based on the observability of those inputs. A fair value hierarchy was established that prioritizes the inputs used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements).
	Level 1 – Quoted prices are available in active markets for identical assets or liabilities as of the reporting date. Active markets are those in which transactions for the asset or liability occur in sufficient frequency and volume to provide pricing information on an ongoing basis. Level 1 primarily consists of financial instruments such as exchange-traded derivatives, listed securities and U.S. government treasury securities.
	Level 2 – Pricing inputs are other than quoted prices in active markets included in Level 1, which are either directly or indirectly observable as of the reporting date. Level 2 includes those financial instruments that are valued using models or other valuation methodologies. These models are primarily industry-standard models that consider various assumptions, including quoted forward prices for commodities, time value, volatility factors and current market and contractual prices for the underlying instruments, as well as other relevant economic measures. Substantially all of these assumptions are observable in the marketplace throughout the full term of the instrument, can be derived from observable data or are supported by observable levels at which transactions are executed in the marketplace. Instruments in this category include non-exchange-traded derivatives such as over-the-counter forwards and options.
	Level 3 – Pricing inputs include significant inputs that are generally less observable than objective sources. These inputs may be used with internally developed methodologies that result in management’s best estimate of fair value. At each balance sheet date, the Company performs an analysis of all applicable instruments and includes in Level 3 all of those whose fair value is based on significant unobservable inputs.
	The following tables set forth by level within the fair value hierarchy the Company’s financial assets and financial liabilities that were measured at fair value on a recurring basis. Assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of assets and liabilities and their placement within the fair value hierarchy levels.
		As of December 31, 2014
		Level 1		Level 2		Level 3		Total
		(in thousands)
	Assets
	Deferred Compensation Plan	$	1,069	$	—	$	—	$	1,069
	Cash Equivalents - Money Market Funds	75,066		—		—		75,066
	Commodity Derivatives	—		195,176		—		195,176
	Liabilities
	Commodity Derivatives	$	—	$	200	$	—	$	200
		As of December 31, 2013
		Level 1		Level 2		Level 3		Total
		(in thousands)
	Assets
	Deferred Compensation Plan	$	941	$	—	$	—	$	941
	Cash Equivalents - Money Market Funds	53		—		—		53
	Commodity Derivatives	—		11,483		—		11,483
	Liabilities
	Commodity Derivatives	$	—	$	14,771	$	—	$	14,771
	All fair values reflected in the table above and on the Consolidated Balance Sheets have been adjusted for non-performance risk. For applicable financial assets carried at fair value, the credit standing of the counterparties is analyzed and factored into the fair value measurement of those assets. In addition, the fair value measurement of a liability has been adjusted to reflect the nonperformance risk of the Company. The following methods and assumptions were used to estimate the fair values of the assets and liabilities in the table above.
	Level 1 Fair Value Measurements – The Company maintains a non-qualified deferred compensation plan (as discussed in more detail in Note 11) which allows certain management employees to defer receipt of a portion of their compensation. The Company maintains assets for the deferred compensation plan in a rabbi trust. The assets of the rabbi trust are invested in publicly traded mutual funds and are recorded in prepayments and other current assets and deferred financing costs and other noncurrent assets on the Consolidated Balance Sheets. The Company also has highly liquid short term investments in money market funds. The deferred compensation plan financial assets are reported at fair value based on active market quotes, which represent Level 1 inputs. The money market fund investments are recorded at carrying value, which approximates fair value, and represents Level 1 inputs. The fair values of the Company’s fixed rate $400.0 million principal 7.625% Senior Notes and $400.0 million principal 7.0% Senior Notes totaled $725.8 million and $847.2 million as of December 31, 2014 and 2013, respectively. The fair values of the Company's fixed rate Senior Notes are based on active market quotes, which represent Level 1 inputs.
	Level 2 Fair Value Measurements – The fair value of oil, natural gas and NGL swaps and forwards are estimated using a combined income and market valuation methodology with a mid-market pricing convention based upon forward commodity price and volatility curves. The curves are obtained from independent pricing services reflecting broker market quotes. The Company did not make any adjustments to the obtained curves. The pricing services publish observable market information from multiple brokers and exchanges. No proprietary models are used by the pricing services for the inputs. The Company utilized the counterparties’ valuations to assess the reasonableness of the Company’s valuations.
	There is no active, public market for the Company’s Amended Credit Facility, Convertible Notes or Lease Financing Obligation. The Amended Credit Facility balance of zero and $115.0 million as of December 31, 2014 and 2013, respectively, approximates its fair value due to its floating rate structure. The Convertible Notes fair value of $25.1 million as of December 31, 2014 and 2013 is measured based on market-based parameters of the various components of the Convertible Notes and over the counter trades. The Lease Financing Obligation fair values of $3.5 million and $41.7 million as of December 31, 2014 and 2013, respectively, are measured based on market-based parameters of comparable term secured financing instruments. The fair value measurements for the Amended Credit Facility, Convertible Notes and Lease Financing Obligation represent Level 2 inputs.
	Level 3 Fair Value Measurements – As of December 31, 2014 and 2013, the Company did not have assets or liabilities that were measured on a recurring basis classified under a Level 3 fair value hierarchy.
	Assets and Liabilities Measured on a Non-recurring Basis
	The Company utilizes fair value on a non-recurring basis to perform impairment tests on its property and equipment when required. During the year ended December 31, 2014, the Company recognized impairment on proved and unproved property of $39.8 million. Included in the total impairment charge of $39.8 million was $21.1 million of impairment charges related to the remaining Powder River Basin assets for which the Company utilized third party purchase offers as the basis for determining fair value. This property was classified as held for sale as of December 31, 2014. The inputs used to determine such fair value for other non-recurring impairment tests are primarily based upon internally developed cash flow models as well as available external market data and would generally be classified within Level 3.
		Net Carrying Value as of December 31, 2014		Impairment for the Year Ended December 31, 2014
				Level 1		Level 2		Level 3
		(in thousands)
	Proved property (1)(2)	$	1,588,038	$	—	$	—	$	15,761
	Unproved property (1)(2)	151,368		—		—		24,082
	-1	See Note 2 for additional details on impairment expense recognized.
	-2	Includes $6.7 million of net proved property and $2.5 million of net unproved property associated with properties held for sale as of December 31, 2014.
	The Company utilizes fair value on a non-recurring basis to perform impairment tests on its property and equipment when required. During the year ended December 31, 2013, the Company recorded impairment charges of $226.6 million on proved and unproved oil and gas properties. Included in the total impairment charge of $226.6 million was $209.5 million of impairment charges related to the West Tavaputs area of the Uinta Basin for which the Company utilized third party purchase offers as the basis for determining fair value. This property was sold in December 2013. The inputs used to determine such fair value for other non-recurring impairment tests are primarily based upon internally developed cash flow models as well as available external market data and would generally be classified within Level 3.
		Net Carrying Value as of December 31, 2013		Impairment for the Year Ended December 31, 2013
				Level 1		Level 2		Level 3
		(in thousands)
	Proved property (1)	$	1,937,913	$	—	$	—	$	206,953
	Unproved property (1)	246,270		—		—		19,598
	-1	See Note 2 for additional details on impairment expense recognized.

Derivative_Instruments

Derivative Instruments	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Derivative Instruments
	The Company uses financial derivative instruments as part of its price risk management program to achieve a more predictable cash flow from its production revenues by reducing its exposure to commodity price fluctuations. The Company has entered into financial commodity swap contracts related to the sale of a portion of the Company’s production. The Company does not enter into derivative instruments for speculative or trading purposes.
	In addition to financial contracts, the Company at times may be party to various physical commodity contracts for the sale of oil, natural gas and NGLs that have varying terms and pricing provisions. These physical commodity contracts qualify for the normal purchase and normal sale exception and, therefore, are not subject to hedge or mark-to-market accounting. The financial impact of physical commodity contracts is included in oil, natural gas and NGL production revenues at the time of settlement.
	All derivative instruments, other than those that meet the normal purchase and normal sale exception, as mentioned above, are recorded at fair value and included on the Consolidated Balance Sheets as assets or liabilities. The following table summarizes the location, as well as the gross and net fair value amounts of all derivative instruments presented on the Consolidated Balance Sheets as of the dates indicated.
		As of December 31, 2014
	Balance Sheet	Gross Amounts of				Gross Amounts				Net Amounts of Assets
		Recognized Assets				Offset in the Balance				Presented in the Balance
						Sheet				Sheet
						(in thousands)
	Derivative assets (current)	$	145,426			$	(200	)	(1)	$	145,226
	Derivative assets (noncurrent)	49,750				—			(1)	49,750
	Total derivative assets	$	195,176			$	(200	)		$	194,976
		Gross Amounts of				Gross Amounts				Net Amounts of Liabilities
		Recognized				Offset in the Balance				Presented in the Balance
		Liabilities				Sheet				Sheet
						(in thousands)
	Derivative liabilities	$	(200	)		$	200		(2)	$	—
	Derivatives and other noncurrent liabilities	—				—			(2)	—			(3)
	Total derivative liabilities	$	(200	)		$	200			$	—
		As of December 31, 2013
	Balance Sheet	Gross Amounts of				Gross Amounts				Net Amounts of Assets
		Recognized Assets				Offset in the Balance				Presented in the Balance
						Sheet				Sheet
						(in thousands)
	Derivative assets (current)	$	8,259			$	(8,086	)	(1)	$	173
	Derivative assets (noncurrent)	3,224				(685		)	(1)	2,539
	Total derivative assets	$	11,483			$	(8,771	)		$	2,712
		Gross Amounts of				Gross Amounts				Net Amounts of Liabilities
		Recognized				Offset in the Balance				Presented in the Balance
		Liabilities				Sheet				Sheet
						(in thousands)
	Derivative liabilities	$	(14,074	)		$	8,086		(2)	$	(5,988	)
	Derivatives and other noncurrent liabilities	(697		)		685			(2)	(12		)	(3)
	Total derivative liabilities	$	(14,771	)		$	8,771			$	(6,000	)
	-1	Amounts are netted against derivative asset balances with the same counterparty, and therefore, are presented as a net asset on the Consolidated Balance Sheets.
	-2	Amounts are netted against derivative liability balances with the same counterparty, and therefore are presented as a net liability on the Consolidated Balance Sheets.
	-3	As of December 31, 2014 and 2013, this line item on the Consolidated Balance Sheets includes $3.0 million and $3.5 million of other noncurrent liabilities, respectively.
	Effective January 1, 2012, the Company elected to discontinue hedge accounting prospectively. As a result, the mark-to-market value of all commodity hedge instruments within AOCI at December 31, 2011 was frozen in AOCI as of the de-designation date and was reclassified into earnings in future periods as the original hedged transactions occurred. All cash flow hedged transactions were completed by December 31, 2014. The following table summarizes the cash flow hedge gains, net of tax, and their locations on the Consolidated Balance Sheets and Consolidated Statements of Operations for the periods indicated:
		Derivatives Qualifying as		Year Ended December 31,
		Cash Flow Hedges		2014				2013				2012
				(in thousands)
	Amount of Gain (Loss) Recognized in AOCI (1)	Commodity Hedges		$	—			$	—			$	—
	Amount of Gain (Loss) Reclassified from AOCI into Income (net of tax) (1)(2)	Commodity Hedges		$	669			$	4,663			$	50,712
	Amount of Gain (Loss) Recognized in Income on Ineffective Hedges	Commodity Hedges		$	—			$	—			$	—
	-1	Presented net of income tax expense of $0.4 million, $2.8 million and $30.5 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	-2	Gains reclassified from AOCI into income are included in the oil, gas and NGL production revenues in the Consolidated Statements of Operations.
	As of December 31, 2014, the Company had financial instruments in place to hedge the following volumes for the periods indicated:
		Year Ending December 31,
		2015			2016			2017
	Oil (Bbls)	4,022,600			1,737,000			365,000
	Natural Gas (MMbtu)	7,207,000			1,830,000			—
	The table below summarizes the commodity derivative gains and losses the Company recognized related to its oil, gas and NGL derivative instruments for the periods indicated:
		Year Ended December 31,
		2014				2013				2012
		(in thousands)
	Commodity derivative settlements on derivatives designated as cash flow hedges (1)	$	1,070			$	7,463			$	81,166
	Total commodity derivative gain (loss) (2)	197,447				(23,068		)		72,759
	-1	Included in oil, gas and NGL production revenues in the Consolidated Statements of Operations.
	-2	Included in commodity derivative gain (loss) in the Consolidated Statements of Operations.
	The Company’s derivative financial instruments are generally executed with major financial or commodities trading institutions that expose the Company to market and credit risks and may, at times, be concentrated with certain counterparties or groups of counterparties. The Company had hedges in place with eight different counterparties as of December 31, 2014. Although notional amounts are used to express the volume of these contracts, the amounts potentially subject to credit risk, in the event of non-performance by the counterparties, are substantially smaller. The creditworthiness of counterparties is subject to continual review by management, and the Company believes all of these institutions currently are acceptable credit risks. Full performance is anticipated, and the Company has no past due receivables from any of its counterparties.
	It is the Company’s policy to enter into derivative contracts with counterparties that are lenders in the Amended Credit Facility, affiliates of lenders in the Amended Credit Facility or potential lenders in the Amended Credit Facility. The Company’s derivative contracts are documented using an industry standard contract known as a Schedule to the Master Agreement and International Swaps and Derivative Association, Inc. ("ISDA") Master Agreement or other contracts. Typical terms for these contracts include credit support requirements, cross default provisions, termination events and set-off provisions. The Company is not required to provide any credit support to its counterparties other than cross collateralization with the properties securing the Amended Credit Facility. The Company has set-off provisions in its derivative contracts with lenders under its Amended Credit Facility which, in the event of a counterparty default, allow the Company to set-off amounts owed to the defaulting counterparty under the Amended Credit Facility or other obligations against monies owed the Company under derivative contracts. Where the counterparty is not a lender under the Company’s Amended Credit Facility, it may not be able to set-off amounts owed by the Company under the Amended Credit Facility, even if such counterparty is an affiliate of a lender under such facility. The Company does not have any derivative balances that are offset by cash collateral.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes
	The expense for income taxes consisted of the following for the periods indicated:
		Year Ended December 31,
		2014			2013			2012
		(in thousands)
	Current:
	Federal	$	1,220		$	(1,233	)	$	966
	State	44			(352		)	886
	Foreign	1			2			1
	Deferred:
	Federal	10,246			(107,300		)	100
	State	6,398			(9,750		)	(317		)
	Total	$	17,909		$	(118,633	)	$	1,636
	Income tax expense differed from the amounts computed by applying the U.S. federal income tax rate of 35% to pretax income from continuing operations as a result of the following:
		Year Ended December 31,
		2014			2013			2012
		(in thousands)
	Income tax expense at the federal statutory rate	$	11,546		$	(108,978	)	$	777
	State income taxes, net of federal tax effect	932			(6,702		)	(269		)
	Incentive stock compensation	199			678			635
	Nondeductible political contributions and lobbying costs	108			96			271
	Nondeductible officer compensation	229			138			—
	Other permanent items	89			52			26
	Deferred tax related to the changes in overall state tax rates	5,230			(3,851		)	310
	Other, net	(424		)	(66		)	(114		)
	Income tax expense (benefit)	$	17,909		$	(118,633	)	$	1,636
	The tax effects of temporary differences that give rise to significant components of the deferred tax assets and deferred tax liabilities at December 31, 2014 and 2013 are presented below:
		As of December 31,
		2014			2013
		(in thousands)
	Current:
	Deferred tax assets (liabilities):
	Derivative instruments	$	(54,933	)	$	(89	)
	Accrued expenses	229			400
	Bad debt expense	5			8
	Prepaid expenses	(702		)	(648		)
	Other	(17		)	130
	Total current deferred tax assets (liabilities)	$	(55,418	)	$	(199	)
	Long-term:
	Deferred tax assets:
	Net operating loss carryforward	$	56,529		$	75,511
	Deferred offering costs	1,182			1,243
	Stock-based compensation	15,767			14,200
	Deferred rent	787			962
	Minimum tax credit carryforward	1,690			688
	Deferred compensation	1,062			999
	State tax credit carryforwards	5,110			5,871
	Production payment loan	—			3,839
	Financing obligation	1,586			16,227
	Other	250			222
	Less: Valuation allowance	(5,110		)	(5,871		)
	Total long-term deferred tax assets	78,853			113,891
	Deferred tax liabilities:
	Oil and gas properties	(182,385		)	(276,523		)
	Long-term derivative instruments	(18,818		)	1,306
	Total long-term deferred tax liabilities	(201,203		)	(275,217		)
	Net long-term deferred tax liabilities	$	(122,350	)	$	(161,326	)
	At December 31, 2014, the Company had approximately $168.2 million of federal tax net operating loss carryforwards which expire beginning in 2027. The Company has a federal alternative minimum tax credit carryforward of $1.7 million, which has no expiration date.
	In assessing the realizability of deferred tax assets, management must consider whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. Management considers all available evidence (both positive and negative) in determining whether a valuation allowance is required. Such evidence includes the scheduled reversal of deferred tax liabilities, projected future taxable income and tax planning strategies in making this assessment, and judgment is required in considering the relative weight of negative and positive evidence. The Company continues to monitor facts and circumstances in the reassessment of the likelihood that operating loss carryforwards, credits and other deferred tax assets will be utilized prior to their expiration. As a result, it may be determined that a deferred tax asset valuation allowance should be established. Any increases or decreases in a deferred tax asset valuation allowance would impact net income through offsetting changes in income tax expense. At December 31, 2014, the Company had approximately $7.9 million of state income tax credit carryforwards that begin expiring in 2018. A valuation allowance against these credits was recorded in 2011. It is currently estimated that the state income tax credits will not be utilized because the Company does not project to have sufficient future taxable income in the appropriate jurisdictions, and therefore the valuation allowance on the full amount of the credit carryforwards will remain.
	At December 31, 2014 and 2013, the Consolidated Balance Sheet reflected a net deferred tax liability of $177.8 million and $161.5 million, respectively.
	The Company accounts for uncertainty in income taxes for tax positions taken or expected to be taken in a tax return. The Company recognizes the tax benefit from an uncertain tax position only if it is more likely than not that the tax position will be sustained upon examination by the taxing authorities, based on the technical merits. The Company did not have any additions, reductions or settlements of unrecognized tax benefits in the years ended December 2014, 2013 and 2012. In 2014, the Company generated no uncertain tax positions.
	The Company’s policy is to classify accrued penalties and interest related to unrecognized tax benefits in the Company’s income tax provision. As of December 31, 2014, the Company did not have any accrued interest or penalties associated with any unrecognized tax benefits, nor was any interest expense recognized during the current year.
	The Company and its subsidiaries file income tax returns in the U.S. federal jurisdiction and in various states. With few exceptions, the Company is subject to U.S. federal tax examination for years 2011 through 2014 and is subject to state tax examination for years 2010 through 2014.

Stockholders_Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Stockholders' Equity	Stockholders' Equity
	Common and Preferred Stock. The Company’s authorized capital structure consists of 75,000,000 shares of preferred stock, par value $0.001 per share and 150,000,000 shares of common stock, par value $0.001 per share. In October 2004, 150,000 shares of $0.001 per share par value preferred stock were designated as Series A Junior Participating Preferred Stock, none of which are outstanding. The remainder of the authorized preferred stock is undesignated. There are no issued and outstanding shares of preferred stock.
	When issued, each share of Series A Junior Participating Preferred Stock will entitle the holder thereof to 1,000 votes on all matters submitted to a vote of the Company’s stockholders.
	Treasury Stock. The Company may occasionally acquire treasury stock, which is recorded at cost, in connection with the vesting and exercise of stock-based awards or for other reasons. As of December 31, 2014, all treasury stock held by the Company was retired.
	The following table reflects the activity in the Company’s common and treasury stock for the periods indicated:
		Year Ended December 31,
		2014			2013			2012
	Common Stock Outstanding:
	Shares at beginning of period	49,152,448			48,150,475			47,809,903
	Exercise of common stock options	7,926			259,699			36,560
	Shares issued for 401(k) plan	36,533			47,235			41,415
	Shares issued for directors' fees	44,551			52,081			12,973
	Shares issued for nonvested equity shares of common stock	857,870			1,081,259			454,666
	Shares retired or forfeited	(572,691	)		(438,301	)		(205,042	)
	Shares at end of period	49,526,637			49,152,448			48,150,475
	Treasury Stock:
	Shares at beginning of period	—			—			—
	Treasury stock acquired	116,813			96,880			92,393
	Treasury stock retired	(116,813	)		(96,880	)		(92,393	)
	Shares at end of period	—			—			—
	Accumulated Other Comprehensive Income. The components of accumulated other comprehensive income and related tax effects for the years ended December 31, 2012, 2013 and 2014 were as follows:
		Gross				Tax Effect				Net of Tax
		(in thousands)
	Accumulated other comprehensive income — December 31, 2011	$	89,714			$	(33,670	)		$	56,044
	Reclassification adjustment for realized gains on hedges included in net income	(81,170		)		30,458				(50,712		)
	Accumulated other comprehensive income — December 31, 2012	$	8,544			$	(3,212	)		$	5,332
	Reclassification adjustment for realized gains on hedges included in net income	(7,465		)		2,802				(4,663		)
	Accumulated other comprehensive income — December 31, 2013	$	1,079			$	(410	)		$	669
	Reclassification adjustment for realized gains on hedges included in net income	(1,079		)		410				(669		)
	Accumulated other comprehensive income — December 31, 2014	$	—			$	—			$	—

Equity_Incentive_Compensation_

Equity Incentive Compensation Plans and Other Employee Benefits	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity Incentive Compensation Plans and Other Employee Benefits	Equity Incentive Compensation Plans and Other Employee Benefits
	The Company maintains various stock-based compensation plans and other employee benefit plans as discussed below. Stock-based compensation is measured at the grant date based on the value of the awards, and the fair value is recognized on a straight-line basis over the requisite service period (usually the vesting period).
	The following table presents the non-cash stock-based compensation related to equity awards for the periods indicated:
		Year Ended December 31,
		2014				2013				2012
		(in thousands)
	Common stock options	$	2,073			$	4,696			$	7,189
	Nonvested equity common stock	6,845				7,492				7,394
	Nonvested equity common stock units (1)	1,065				1,272				708
	Nonvested performance-based equity	990				2,174				1,079
	Total	$	10,973			$	15,634			$	16,370
	-1	Includes non-cash stock-based compensation related to director fees of $0.1 million, $0.4 million and $0.2 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	Unrecognized compensation cost as of December 31, 2014 was $15.7 million related to grants of nonvested stock options and nonvested equity shares of common stock that are expected to be recognized over a weighted-average period of 2.3 years.
	Stock Options and Nonvested Equity Shares. In May 2012, the Company’s stockholders approved and the Company adopted its 2012 Equity Incentive Plan (the "2012 Incentive Plan"). The purpose of the 2012 Incentive Plan is to enhance the Company’s ability to attract and retain officers, employees and directors and to provide such persons with an interest in the Company aligned with the interests of stockholders. The 2012 Incentive Plan provides for the grant of stock options (including incentive stock options and non-qualified stock options) and other awards, including performance units, performance shares, share awards, share units, restricted stock, cash incentive, and stock appreciation rights or SARs.
	The aggregate number of shares that the Company may issue under the 2012 Incentive Plan may not exceed 2,051,402 shares, subject to adjustment for future stock splits, stock dividends and similar changes in the Company’s capitalization. Shares underlying grants that expire without being exercised or are forfeited are available for grant under the 2012 Incentive Plan. The aggregate number of shares of common stock subject to options, stock appreciation rights, or performance-based awards granted to a participant during any calendar year may not exceed 500,000 shares. The 2012 Incentive Plan provides that all awards granted under the 2012 Incentive Plan expire not more than 10 years from the grant date and have an exercise price of no less than the closing price of the Company’s common stock on the date of grant.
	Currently, the Company’s practice is to issue new shares upon stock option exercise. The Company does not expect to repurchase any shares in the open market or issue treasury shares to settle any such exercises. For the years ended December 31, 2014, 2013 and 2012, the Company did not pay cash to repurchase any stock option exercises.
	The fair value of each share-based option award under all of the Company’s plans is estimated on the date of grant using a Black-Scholes pricing model that incorporates the assumptions noted in the following table. Estimated expected volatilities were based upon historical volatility of the Company’s common stock. The Company does not expect to declare or pay dividends in the foreseeable future; thus, the Company used a 0% expected dividend yield, which is comparable to most of its peers in the industry. The expected terms range from 0.09 years to 6.0 years, or a weighted average of 4.3 years to 4.6 years, based on 25% of each grant’s vesting on each anniversary date and factoring in potential blackout dates, historic exercises and expectations of future employee behavior. The risk-free rate is based on the U.S. Treasury yield curve in effect on the date of grant and extrapolated to approximate the expected life of the award. The Company estimated a 4% to 10% annual compounded forfeiture rate for the year 2012 based on historical employee turnover and actual forfeitures. The Company did not grant any share-based option awards during the years 2014 or 2013.
			2012
	Weighted average volatility		51	%
	Expected dividend yield		—	%
	Weighted average expected term (in years)		4.3
	Weighted average risk-free rate		1.8	%
	A summary of share-based option activity under all the Company's plans as of December 31, 2014, and changes during the year then ended, is presented below:
		Shares			Weighted Average				Weighted Average		Aggregate
					Exercise Price				Remaining		Intrinsic Value
									Contractual Term
									(in years)
	Outstanding at January 1, 2014	1,748,696			$	32.66
	Granted	—			$	—
	Exercised	(7,926	)		$	18.22
	Forfeited or expired	(401,405	)		$	33.56
	Outstanding at December 31, 2014	1,339,365			$	32.47			1.37		$	—
	Vested and expected to vest, at December 31, 2014 through the life of the options	1,332,062			$	30.33			1.92		$	—
	Vested and exercisable at December 31, 2014	1,151,004			$	33.05			1.6		$	—
	The per share weighted-average grant date fair value of options granted for the year ended December 31, 2012 was $11.02. The total intrinsic value of options exercised for the years ended December 31, 2014, 2013 and 2012 were $0.1 million, $0.5 million and $0.4 million, respectively. With respect to stock option exercises, the Company received $0.1 million, $6.4 million, and $0.7 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	A summary of the Company’s nonvested equity shares of common stock as of December 31, 2014, 2013 and 2012, and changes during the years then ended, is presented below:
		Year Ended December 31,
		2014							2013					2012
		Shares			Weighted				Shares			Weighted		Shares		Weighted
					Average							Average				Average
					Grant Date							Grant Date				Grant Date
					Fair							Fair				Fair
					Value							Value				Value
	Outstanding at January 1,	756,118			$	22.17			579,188			$	31.02	639,628		$	35.12
	Granted	542,209			$	22			630,715			$	17.98	274,679		$	25.62
	Vested	(292,168	)		$	24.05			(270,482	)		$	29.82	(241,736	)	$	34.61
	Forfeited or expired	(213,095	)		$	21.99			(183,303	)		$	24.87	(93,383	)	$	33.39
	Outstanding at December 31,	793,064			$	21.47			756,118			$	22.17	579,188		$	31.02
	Equity common stock units were issued beginning on July 1, 2012 and will be converted to shares of common stock as they vest. As of December 31, 2014, equity common stock units have only been issued for payment of director fees. A summary of the Company’s nonvested equity share units of common stock as of December 31, 2014, 2013 and 2012, and changes during the years then ended, is presented in the table below:
		Year Ended December 31,
		2014							2013					2012
		Shares			Weighted				Shares			Weighted		Shares		Weighted
					Average							Average				Average
					Grant Date							Grant Date Fair				Grant Date Fair
					Fair							Value				Value
					Value
	Outstanding at January 1,	55,778			$	19.35			49,185			$	18.5	—		$	—
	Granted	45,928			$	24.49			56,464			$	22.33	58,983		$	18.83
	Vested	(46,761	)		$	22.25			(49,871	)		$	18.96	(9,798	)	$	20.51
	Forfeited or expired	—			$	—			—			$	—	—		$	—
	Outstanding at December 31,	54,945			$	23.84			55,778			$	19.35	49,185		$	18.5
	The fair value of equity awards vested for the years ended December 31, 2014, 2013 and 2012 was $8.0 million, $8.1 million and $8.6 million, respectively.
	Performance Share Programs
	2014 Program. In February 2014, the Compensation Committee of the Board of Directors of the Company approved a new performance share program (the "2014 Program") pursuant to the 2012 Equity Incentive Plan. The performance-based awards contingently vest in May 2017, depending on the level at which the performance goals are achieved. The performance goals, which will be measured over the three year period ending December 31, 2016, consist of the Company's total shareholder return ("TSR") ranking relative to a defined peer group's individual TSRs ("Relative TSR") (weighted at 60%) and the percentage change in discretionary cash flow per debt adjusted share relative to a defined peer group's percentage calculation ("DCF per Debt Adjusted Share") (weighted at 40%). The Relative TSR and DCF per Debt Adjusted Share goals will vest at 25% of the total award for performance met at the threshold level, 100% at the target level and 200% at the stretch level. If the actual results for a metric are between the threshold and target levels or between the target and stretch levels, the vested number of shares will be prorated based on the actual results compared to the threshold, target and stretch goals. If the threshold metrics are not met, no shares will vest. In any event, the total number of shares of common stock that could vest will not exceed 200% of the original number of performance shares granted. At the end of the three year vesting period, any shares that have not vested will be forfeited. A total of 315,661 shares were granted under this program during the year ended December 31, 2014. All compensation expense related to the TSR metric will be recognized if the requisite service period is fulfilled, even if the market condition is not achieved. All compensation expense related to the DCF per Debt Adjusted Share metric will be based upon the number of shares expected to vest at the end of the three year period.
2013 Program. In February 2013, the Compensation Committee approved a new performance share program (the "2013 Program") pursuant to the 2012 Equity Incentive Plan. The performance-based awards contingently vest in May 2016, depending on the level at which the performance goals are achieved. The performance goals, which will be measured over the three year period ending December 31, 2015, consist of the Company's Relative TSR (weighted at 33 1/3%), the percentage change in discretionary cash flow per debt adjusted share relative to a defined peer group's percentage calculation ("DCF per Debt Adjusted Share") (weighted at 33 1/3%) and percentage change in proved oil, natural gas and NGL reserves per debt adjusted share ("Reserves per Debt Adjusted Share") (weighted at 33 1/3%). The Relative TSR and DCF per Debt Adjusted Share goals will vest at 25% of the total award for performance met at the threshold level, 100% at the target level and 200% at the stretch level. The Reserves per Debt Adjusted Share goal will vest at 50% of the total award for performance met at the threshold level, 100% at the target level and 200% at the stretch level. If the actual results for a metric are between the threshold and target levels or between the target and stretch levels, the vested number of shares will be prorated based on the actual results compared to the threshold, target and stretch goals. If the threshold metrics are not met, no shares will vest. In any event, the total number of shares of common stock that could vest will not exceed 200% of the original number of performance shares granted. At the end of the three year vesting period, any shares that have not vested will be forfeited. A total of 450,544 shares were granted under this program during the year ended December 31, 2013. All compensation expense related to the Relative TSR metric will be recognized if the requisite service period is fulfilled, even if the market condition is not achieved. All compensation expense related to the DCF per Debt Adjusted Share metric and the Reserves per Debt Adjusted Share metric will be based upon the number of shares expected to vest at the end of the three year period.
2012 Program. In March 2012, the Compensation Committee approved a new performance share program (the "2012 Program"). The performance-based awards contingently vest in May 2015, depending on the level at which the performance goals are achieved. The performance goals, which will be measured over the three year period ending December 31, 2014, consist of the Company's TSR ranking relative to a defined peer group's individual TSR (weighted at 33 1/3%), the percentage change in DCF per Debt Adjusted Share relative to a defined peer group's percentage calculation (weighted at 33 1/3%) and the change in proved oil and natural gas reserves per debt adjusted share (weighted at 33 1/3%). Fifty percent of the total award will vest for performance met at the threshold level, 100% will vest at the target level and 200% will vest at the stretch level. If the actual results for a metric are between the threshold and target levels or between the target and stretch levels, the vested number of shares will be adjusted on a prorated basis of the actual results compared to the threshold, target and stretch goals. If the threshold metrics are not met, no shares will vest. In any event, the total number of shares of common stock that could vest will not exceed 200% of the original number of performance shares granted. At the end of the three year vesting period, any shares that have not vested will be forfeited. All compensation expense related to the TSR metric will be recognized if the requisite service period is fulfilled, even if the market condition is not achieved. All compensation expense related to the DCF per Debt Adjusted Share and oil and natural gas reserves per debt adjusted share metrics will be based upon the number of shares expected to vest at the end of the three year period. A total of 179,987 shares were granted under this program during the year ended December 31, 2012. Based upon the Company's performance through 2014, none of the 2012 Program performance shares will vest in May 2015.
2010 Program. In February 2010, the Compensation Committee approved a performance share program (the "2010 Program"). Upon commencement of the 2010 Program and during each subsequent year of the 2010 Program through 2013, the Compensation Committee met to approve target and stretch goals for certain operational or financial metrics that are selected by the Compensation Committee for the upcoming year and to determine whether metrics for the prior year have been met. As new goals are established each year for the performance-based awards, a new grant date and a new fair value are created for financial reporting purposes for those shares that could potentially vest in the upcoming year. Compensation expense is recognized based upon an estimate of the extent to which the performance goals would be met. If such goals are not met, no compensation expense is recognized and any previously recognized compensation expense is reversed.
The 2010 Program has both performance-based and market-based goals. All compensation expense related to the market-based goals will be recognized if the requisite service period is fulfilled, even if the market condition is not achieved. Based on Company performance in 2010, 2011, 2012 and 2013, 25.9%, 26.6%, 0.0% and 19.8%, respectively, of the 2010 Program performance-based shares vested in February 2011, February 2012, February 2013 and February 2014, respectively, for a total of 72.3% of the total performance-based shares vested over the four year vesting period. A total of 59,582, 57,944, zero and 21,968 shares vested in February 2011, February 2012, February 2013 and February 2014, respectively.
Based on the 2010 Program market-based goals, which were based on the Company's TSR ranking relative to a defined peer group's individual TSR, 37.5%, 12.5%, 0.0% and 33.4% vested in February 2011, 2012, 2013 and 2014, respectively, based on the Company's rankings as of December 31, 2010, 2011, 2012, and 2013, respectively, for a total of 83.4% of the total market-based shares vested over the four year vesting period. A total of 21,574, 6,801, zero and 9,242 shares vested in February 2011, February 2012, February 2013 and February 2014, respectively.
A summary of the Company's non-vested performance-based equity shares of common stock as of December 31, 2014, 2013 and 2012, and changes during the years then ended, is presented below:
	Year Ended December 31,
	2014							2013					2012
	Shares			Weighted				Shares			Weighted		Shares		Weighted
				Average							Average				Average
				Grant Date							Grant Date				Grant Date
				Fair							Fair				Fair
				Value							Value				Value
Outstanding at January 1,	584,032			$	19.8			291,606			$	26.85	195,630		$	33.36
Vested	(42,833	)		$	19.51			—			$	—	(64,745	)	$	39.9
Modified, performance goals revised (1)	—			$	—			(108,933	)		$	27.75	(121,191	)	$	39.9
Modified, performance goals revised (1)	—			$	—			108,933			$	18.18	121,191		$	27.75
Granted	315,661			$	23.86			450,544			$	19.99	179,987		$	27.57
Forfeited or expired	(242,783	)		$	22.13			(158,118	)		$	22.52	(19,266	)	$	33.82
Outstanding at December 31,	614,077			$	19.62			584,032			$	19.8	291,606		$	26.85
-1	As the Compensation Committee approved new performance metrics for the vesting of performance shares in the upcoming year, a new grant date was then created for any unvested awards that were granted in previous years, and a new fair value was established for financial reporting purposes.
The fair value of the performance-based shares vested in the years ended December 31, 2014 and 2012 was $0.8 million and $2.6 million, respectively.
Director Fees. The Company's non-employee, or outside, directors, may elect to receive all or a portion of their annual retainer and meeting fees in the form of restricted stock units ("RSUs"), which are settled with shares of the Company's common stock, issued pursuant to the Company's 2012 Incentive Plan. After each quarter, RSUs with a value equal to the fees payable for that quarter, calculated using the closing price for the Company's common stock on the last trading day of the quarter, will be delivered to each outside director who elected before that quarter to receive RSUs for payment of director fees. These nonvested RSUs will vest immediately at the end of the applicable quarter. Once vested, the RSUs will settle at the end of the applicable quarter or such later date elected by the director.
A summary of the Company's directors' fees and equity-based compensation for the years ended December 31, 2014, 2013 and 2012 is presented below:
	Year Ended December 31,
	2014				2013				2012
Director fees (shares)	3,928				16,151				12,973
Stock-based compensation (in thousands)	$	75			$	351			$	276
Other Employee Benefits-401(k) Savings Plan. The Company has an employee-directed 401(k) savings plan (the "401(k) Plan") for all eligible employees over the age of 21. Under the 401(k) Plan, employees may make voluntary contributions based upon a percentage of their pretax income, subject to statutory limitations.
The Company matches 100% of each employee's contribution, up to 6% of the employee's pretax income, with 50% of the match made with the Company's common stock. The Company's cash and common stock contributions are fully vested upon the date of match, and employees can immediately sell the portion of the match made with the Company's common stock. The Company made matching cash and common stock contributions of $1.7 million, $1.9 million and $2.0 million for the years ended December 31, 2014, 2013 and 2012, respectively.
Deferred Compensation Plan. In 2010, the Company adopted a non-qualified deferred compensation plan for certain employees and officers whose eligibility to participate in the plan was determined by the Compensation Committee of the Company's Board of Directors. The Company makes matching cash contributions on behalf of eligible employees up to 6% of the employee's cash compensation once the contribution limits are reached on the Company's 401(k) Plan. All amounts deferred and matched under the plan vest immediately. Deferred compensation, including accumulated earnings on the participant-directed investment selections, is distributable in cash at participant-specified dates or upon retirement, death, disability, change in control or termination of employment.
The table below summarizes the activity in the plan during the years ended December 31, 2014 and 2013, and the Company’s ending deferred compensation liability as of December 31, 2014 and 2013:
	Year Ended December 31,
	2014				2013
	(in thousands)
Beginning deferred compensation liability balance	$	941			$	966
Employee contributions	441				206
Company matching contributions	160				115
Distributions	(503		)		(441		)
Participant earnings (losses)	30				95
Ending deferred compensation liability balance	$	1,069			$	941
Amount to be paid within one year	$	220			$	451
Remaining balance to be paid beyond one year	$	849			$	490
The Company has established a rabbi trust to offset the deferred compensation liability and protect the interests of the plan participants. The investments in the rabbi trust seek to offset the change in the value of the related liability. As a result, there is no expected impact on earnings or earnings per share from the changes in market value of the investment assets because the changes in market value of the trust assets are offset by changes in the value of the deferred compensation plan liability. The gains and losses from changes in fair value of the investments are included in interest and other income in the Consolidated Statements of Operations.
The following table represents the Company's activity in the investment assets held in the rabbi trust during the years ended December 31, 2014 and 2013:
	Year Ended December 31,
	2014				2013
	(in thousands)
Beginning investment balance	$	941			$	966
Investment purchases	601				321
Distributions	(503		)		(441		)
Earnings (losses)	30				95
Ending investment balance	$	1,069			$	941

Significant_Customers_and_Othe

Significant Customers and Other Concentrations	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Significant Customers and Other Concentrations	Significant Customers and Other Concentrations
	Significant Customers. During 2014, two customers individually accounted for over 10% of the Company's oil, gas and NGL production revenues. During 2013, one customer individually accounted for over 10% of the Company’s oil, gas and NGL production revenues. During 2012, two customers individually accounted for over 10% of the Company’s oil, gas and NGL production revenues. Although diversified among many companies, collectability is dependent upon the financial stability of each individual company and is influenced by the general economic conditions of the industry. Management believes that the loss of any individual purchaser would not have a long-term material adverse impact on the financial position or results of operations of the Company.
	Concentrations of Market Risk. The future results of the Company’s oil and gas operations will be affected by the market prices of oil, natural gas and NGLs. A readily available market for oil, natural gas and NGLs in the future will depend on numerous factors beyond the control of the Company, including weather, imports, marketing of competitive fuels, proximity and capacity of oil and gas pipelines and other transportation facilities, any oversupply or undersupply of oil, gas and NGLs, the regulatory environment, the economic environment and other regional, national and international economic and political events, none of which can be predicted with certainty.
	The Company operates in the exploration, development and production phase of the oil and gas industry. Its receivables include amounts due from purchasers of oil and gas production and amounts due from joint venture partners for their respective portions of operating expenses and exploration and development costs. The Company believes that no single customer or joint venture partner exposes the Company to significant credit risk. While certain of these customers and joint venture partners are affected by periodic downturns in the economy in general or in their specific segment of the natural gas or oil industry, the Company believes that its level of credit-related losses due to such economic fluctuations has been and will continue to be immaterial to the Company’s results of operations in the long-term. Trade receivables are generally not collateralized. The Company analyzes customers’ and joint venture partners’ historical credit positions and payment histories prior to extending credit.
	Concentrations of Credit Risk. Derivative financial instruments that hedge the price of oil, natural gas and NGLs are generally executed with major financial or commodities trading institutions which expose the Company to market and credit risks and may, at times, be concentrated with certain counterparties or groups of counterparties. The Company’s policy is to execute financial derivatives only with major, creditworthy financial institutions. The Company has placed derivative instruments with eight different counterparties, of which all are lenders or affiliates of lenders in the Amended Credit Facility.
	The creditworthiness of counterparties is subject to continuing review, and the Company believes all of these institutions currently are acceptable credit risks. Full performance is anticipated, and the Company has no past due receivables from any of its counterparties. Where the counterparty is a lender under the Amended Credit Facility, the counterparty risk is mitigated to the extent that the Company is indebted to such lender under the Amended Credit Facility.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies
	Lease Financing Obligation. The Company has a Lease Financing Obligation with Bank of America Leasing & Capital, LLC as the lead bank as discussed in Note 5. The aggregate undiscounted minimum future lease payments, including both principal and interest components, are presented below:
		As of December 31, 2014
		(in thousands)
	2015	$	537
	2016	537
	2017	537
	2018	537
	2019	1,826
	Thereafter	—
	Total	$	3,974
	Transportation Charges. The Company entered into two firm transportation contracts to provide capacity on natural gas pipeline systems. The remaining term on these contracts is six years. The contracts require the Company to pay transportation charges regardless of the amount of pipeline capacity utilized by the Company. Beginning October 1, 2014, these transportation costs are included in unused commitments expense in the Consolidated Statements of Operations. As a result of the divestitures discussed in Note 4, the Company will likely not utilize the firm capacity on the natural gas pipelines.
	The amounts in the table below represent the Company's future minimum transportation charges.
		As of December 31, 2014
		(in thousands)
	2015	$	17,742
	2016	18,692
	2017	18,692
	2018	18,692
	2019	18,692
	Thereafter	29,595
	Total	$	122,105
	Purchase Commitments. The Company has one take-or-pay purchase agreement for supply of carbon dioxide ("CO2"), which has a total financial commitment of $1.7 million. The CO2 is for use in fracture stimulation operations. Under this contract, the Company is obligated to purchase a minimum monthly volume at a set price. If the Company takes delivery of less than the minimum required amount, the Company is responsible for full payment (deficiency payment) in December 2015.
	Lease and Other Commitments. The Company leases office space, vehicles and certain equipment under non-cancelable operating leases. Additionally, the Company has entered into various long-term agreements for telecommunication services.
	The Company has entered into a sales throughput contract in the South Altamont area of the Uinta Oil Basin. Under this contract, the Company is obligated to sell and deliver a minimum volume commitment ("MVC") of 450.0 MMcf for the period of December 1, 2014 to November 30, 2015. If the minimum volume is not delivered, the Company must make a deficiency payment in the amount of up to $0.8 million. This contract replaces the initial capital expenditures associated with the connection of South Altamont wells that would otherwise be incurred as connected. As of December 31, 2014, the Company had satisfied approximately 19.3 MMcf of this commitment, resulting in an estimated deficiency payment of up to $0.7 million due December 1, 2015.
	Future minimum annual payments under lease and other agreements are as follows:
		As of December 31, 2014
		(in thousands)
	2015	$	4,204
	2016	2,838
	2017	2,690
	2018	2,525
	2019	634
	Thereafter	—
	Total	$	12,891
	Litigation. The Company is subject to litigation, claims and governmental and regulatory proceedings arising in the course of ordinary business. It is the opinion of the Company’s management that current claims and litigation involving the Company are not likely to have a material adverse effect on its consolidated balance sheets, cash flows or statements of operations.

Guarantor_Subsidiaries

Guarantor Subsidiaries	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Guarantor Subsidiaries	Guarantor Subsidiaries
	In addition to the Amended Credit Facility, the 7.625% Senior Notes, the 7.0% Senior Notes and the Convertible Notes, which are registered securities, are jointly and severally guaranteed on a full and unconditional basis by the Company's 100% owned subsidiaries ("Guarantor Subsidiaries"). Presented below are the Company’s condensed consolidating balance sheets, statements of operations, statements of other comprehensive income (loss) and statements of cash flows, as required by Rule 3-10 of Regulation S-X of the Securities Exchange Act of 1934, as amended.
	During the three months ended June 30, 2014, Bill Barrett Corporation, as parent, merged two of the Company's 100% owned subsidiaries, CBM Production Company and GB Acquisition Corporation, into the parent company. The condensed consolidating financial statements reflect the new guarantor structure for all periods presented.
	The following condensed consolidating financial statements have been prepared from the Company’s financial information on the same basis of accounting as the Consolidated Financial Statements. Investments in the subsidiaries are accounted for under the equity method. Accordingly, the entries necessary to consolidate the Company and the Guarantor Subsidiaries are reflected in the intercompany eliminations column.
	Condensed Consolidating Balance Sheets
		As of December 31, 2014
		Parent			Guarantor			Intercompany			Consolidated
		Issuer			Subsidiaries			Eliminations
		(in thousands)
	Assets:
	Current assets	$	426,103		$	2		$	—		$	426,105
	Property and equipment, net	1,672,513			80,608			—			1,753,121
	Intercompany receivable (payable)	59,592			(59,592		)	—			—
	Investment in subsidiaries	18,647			—			(18,647		)	—
	Noncurrent assets	65,258			—			—			65,258
	Total assets	$	2,242,113		$	21,018		$	(18,647	)	$	2,244,484
	Liabilities and Stockholders’ Equity:
	Current liabilities	$	263,649		$	1,038		$	—		$	264,687
	Long-term debt	803,222			—			—			803,222
	Deferred income taxes	122,350			—			—			122,350
	Other noncurrent liabilities	23,404			1,333			—			24,737
	Stockholders’ equity	1,029,488			18,647			(18,647		)	1,029,488
	Total liabilities and stockholders’ equity	$	2,242,113		$	21,018		$	(18,647	)	$	2,244,484
		As of December 31, 2013
		Parent			Guarantor			Intercompany			Consolidated
		Issuer			Subsidiaries			Eliminations
		(in thousands)
	Assets:
	Current assets	$	154,986		$	2,261		$	—		$	157,247
	Property and equipment, net	2,127,624			74,872			—			2,202,496
	Intercompany receivable (payable)	59,076			(59,076		)	—			—
	Investment in subsidiaries	12,063			—			(12,063		)	—
	Noncurrent assets	21,770			—			—			21,770
	Total assets	$	2,375,519		$	18,057		$	(12,063	)	$	2,381,513
	Liabilities and Stockholders’ Equity:
	Current liabilities	$	192,106		$	613		$	—		$	192,719
	Long-term debt	979,082			—			—			979,082
	Deferred income taxes	158,071			3,255			—			161,326
	Other noncurrent liabilities	40,542			2,126			—			42,668
	Stockholders’ equity	1,005,718			12,063			(12,063		)	1,005,718
	Total liabilities and stockholders’ equity	$	2,375,519		$	18,057		$	(12,063	)	$	2,381,513
	Condensed Consolidating Statements of Operations
		Year Ended December 31, 2014
		Parent			Guarantor			Intercompany			Consolidated
		Issuer			Subsidiaries			Eliminations
		(in thousands)
	Operating and other revenues	$	447,907		$	24,384		$	—		$	472,291
	Operating expenses	(497,258		)	(17,800		)	—			(515,058		)
	General and administrative	(53,361		)	—			—			(53,361		)
	Interest income and other income (expense)	129,118			—			—			129,118
	Income (loss) before income taxes and equity in earnings (loss) of subsidiaries	26,406			6,584			—			32,990
	Provision for income taxes	(17,909		)	—			—			(17,909		)
	Equity in earnings (loss) of subsidiaries	6,584			—			(6,584		)	—
	Net income (loss)	$	15,081		$	6,584		$	(6,584	)	$	15,081
		Year Ended December 31, 2013
		Parent			Guarantor			Intercompany			Consolidated
		Issuer			Subsidiaries			Eliminations
		(in thousands)
	Operating and other revenues	$	538,932		$	29,161		$	—		$	568,093
	Operating expenses	(655,219		)	(27,949		)	—			(683,168		)
	General and administrative	(64,902		)	—			—			(64,902		)
	Interest income and other income (expense)	(131,389		)	—			—			(131,389		)
	Income (loss) before income taxes and equity in earnings (loss) of subsidiaries	(312,578		)	1,212			—			(311,366		)
	Provision for income taxes	118,633			—			—			118,633
Equity in earnings (loss) of subsidiaries	1,212			—			(1,212		)	—
Net income (loss)	$	(192,733	)	$	1,212		$	(1,212	)	$	(192,733	)
	Year Ended December 31, 2012
	Parent			Guarantor			Intercompany			Consolidated
	Issuer			Subsidiaries			Eliminations
	(in thousands)
Operating and other revenues	$	683,319		$	16,876		$	—		$	700,195
Operating expenses	(599,215		)	(9,105		)	—			(608,320		)
General and administrative	(68,666		)	—			—			(68,666		)
Interest and other income (expense)	(20,991		)	—			—			(20,991		)
Income (loss) before income taxes and equity in earnings (loss) of subsidiaries	(5,553		)	7,771			—			2,218
Provision for income taxes	(1,636		)	—			—			(1,636		)
Equity in earnings (loss) of subsidiaries	7,771			—			(7,771		)	—
Net income (loss)	$	582		$	7,771		$	(7,771	)	$	582
Condensed Consolidating Statements of Comprehensive Income (Loss)
	Year Ended December 31, 2014
	Parent			Guarantor			Intercompany			Consolidated
	Issuer			Subsidiaries			Eliminations
	(in thousands)
Net Income (Loss)	$	15,081		$	6,584		$	(6,584	)	$	15,081
Other Comprehensive Income (Loss), net of tax:
Effect of derivative financial instruments	(669		)	—			—			(669		)
Other comprehensive loss	(669		)	—			—			(669		)
Comprehensive Income (Loss)	$	14,412		$	6,584		$	(6,584	)	$	14,412
	Year Ended December 31, 2013
	Parent			Guarantor			Intercompany			Consolidated
	Issuer			Subsidiaries			Eliminations
	(in thousands)
Net Income (Loss)	$	(192,733	)	$	1,212		$	(1,212	)	$	(192,733	)
Other Comprehensive Income (Loss), net of tax:
Effect of derivative financial instruments	(4,663		)	—			—			(4,663		)
Other comprehensive loss	(4,663		)	—			—			(4,663		)
Comprehensive Income (Loss)	$	(197,396	)	$	1,212		$	(1,212	)	$	(197,396	)
	Year Ended December 31, 2012
	Parent			Guarantor			Intercompany			Consolidated
	Issuer			Subsidiaries			Eliminations
	(in thousands)
Net Income (Loss)	$	582		$	7,771		$	(7,771	)	$	582
Other Comprehensive Income (Loss), net of tax:
Effect of derivative financial instruments	(50,712		)	—			—			(50,712		)
Other comprehensive loss	(50,712		)	—			—			(50,712		)
Comprehensive Income (Loss)	$	(50,130	)	$	7,771		$	(7,771	)	$	(50,130	)
Condensed Consolidating Statements of Cash Flows
	Year Ended December 31, 2014
	Parent			Guarantor			Intercompany			Consolidated
	Issuer			Subsidiaries			Eliminations
	(in thousands)
Cash flows from operating activities	$	241,628		$	20,089		$	—		$	261,717
Cash flows from investing activities:
Additions to oil and gas properties, including acquisitions	(562,141		)	(18,802		)	—			(580,943		)
Additions to furniture, fixtures and other	(3,658		)	—			—			(3,658		)
Proceeds from sale of properties and other investing activities	553,477			1,819			—			555,296
Intercompany transfers	3,156			—			(3,156		)	—
Cash flows from financing activities:
Proceeds from debt	165,000			—			—			165,000
Principal and redemption premium payments on debt	(283,546		)	—			—			(283,546		)
Intercompany transfers	—			(3,156		)	3,156			—
Other financing activities	(2,557		)	—			—			(2,557		)
Change in cash and cash equivalents	111,359			(50		)	—			111,309
Beginning cash and cash equivalents	54,545			50			—			54,595
Ending cash and cash equivalents	$	165,904		$	—		$	—		$	165,904
	Year Ended December 31, 2013
	Parent			Guarantor			Intercompany			Consolidated
	Issuer			Subsidiaries			Eliminations
	(in thousands)
Cash flows from operating activities	$	241,911		$	23,354		$	—		$	265,265
Cash flows from investing activities:
Additions to oil and gas properties, including acquisitions	(408,441		)	(37,038		)	—			(445,479		)
Additions to furniture, fixtures and other	(2,254		)	—			—			(2,254		)
Proceeds from sale of properties and other investing activities	310,704			—			—			310,704
Cash flows from financing activities:
Proceeds from debt	420,000			—			—			420,000
Principal and redemption premium payments on debt	(576,422		)	—			—			(576,422		)
Intercompany transfers	(13,684		)	13,684			—			—
Other financing activities	3,336			—			—			3,336
Change in cash and cash equivalents	(24,850		)	—			—			(24,850		)
Beginning cash and cash equivalents	79,395			50			—			79,445
Ending cash and cash equivalents	$	54,545		$	50		$	—		$	54,595
	Year Ended December 31, 2012
	Parent			Guarantor			Intercompany			Consolidated
	Issuer			Subsidiaries			Eliminations
	(in thousands)
Cash flows from operating activities	$	372,331		$	16,105		$	—		$	388,436
Cash flows from investing activities:
Additions to oil and gas properties, including acquisitions	(925,012		)	(33,642		)	—			(958,654		)
Additions to furniture, fixtures and other	(7,231		)	—			—			(7,231		)
Proceeds from sale of properties and other investing activities	328,888			—			—			328,888
Cash flows from financing activities:
Proceeds from debt	875,826			—			—			875,826
Principal and redemption premium payments on debt	(595,386		)	—			—			(595,386		)
Intercompany transfers	(17,537		)	17,537			—			—
Other financing activities	(9,765		)	—			—			(9,765		)
Change in cash and cash equivalents	22,114			—			—			22,114
Beginning cash and cash equivalents	57,281			50			—			57,331
Ending cash and cash equivalents	$	79,395		$	50		$	—		$	79,445

Summary_of_Significant_Account1

Summary of Significant Accounting Policies - (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation. The accompanying Consolidated Financial Statements include the accounts of the Company. These statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP"). All intercompany accounts and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates. In the course of preparing the Company’s financial statements in accordance with GAAP, management makes various assumptions, judgments and estimates to determine the reported amount of assets, liabilities, revenues and expenses and in the disclosure of commitments and contingencies. Changes in these assumptions, judgments and estimates will occur as a result of the passage of time and the occurrence of future events and, accordingly, actual results could differ from amounts initially established.
	Areas requiring the use of assumptions, judgments and estimates relate to the expected cash settlement of the Company’s 5% Convertible Senior Notes due 2028 ("Convertible Notes") in computing diluted earnings per share, volumes of oil, natural gas and NGL reserves used in calculating depreciation, depletion and amortization ("DD&A"), the amount of expected future cash flows used in determining possible impairments of oil and gas properties and the amount of future capital costs used in these calculations. Assumptions, judgments and estimates also are required in determining asset retirement obligations, the timing of dry hole costs, impairments of proved and unproved properties, valuing deferred tax assets and estimating fair values of derivative instruments and stock-based payment awards.
Oil and Gas Properties	Oil and Gas Properties. The Company’s oil, gas and NGL exploration and production activities are accounted for using the successful efforts method. Under this method, all property acquisition costs and costs of exploratory and development wells are capitalized when incurred, pending determination of whether the well has found proved reserves. If an exploratory well does not find proved reserves, the costs of drilling the well are charged to expense and included within cash flows from investing activities in the Consolidated Statements of Cash Flows. If an exploratory well does find proved reserves, the costs remain capitalized and are included within additions to oil and gas properties within cash flows from investing activities in the Consolidated Statements of Cash Flows when paid. The costs of development wells are capitalized whether proved reserves are added or not. Oil and gas lease acquisition costs are also capitalized. Upon sale or retirement of depreciable or depletable property, the cost and related accumulated DD&A are eliminated from the accounts and the resulting gain or loss is recognized.
	Other exploration costs, including certain geological and geophysical expenses and delay rentals for oil and gas leases, are charged to expense as incurred. The sale of a partial interest in a proved property is accounted for as a cost recovery and no gain or loss is recognized as long as this treatment does not significantly affect the unit-of-production amortization rate. Maintenance and repairs are charged to expense, and renewals and betterments are capitalized to the appropriate property and equipment accounts.
	Unproved oil and gas property costs are transferred to proved oil and gas properties if the properties are subsequently determined to be productive or are assigned proved reserves. Proceeds from sales of partial interests in unproved leases are accounted for as a recovery of cost without recognizing any gain until all costs are recovered. Unproved oil and gas properties are assessed periodically for impairment based on remaining lease terms, drilling results, reservoir performance, commodity price outlooks, future plans to develop acreage and other relevant matters.
	Materials and supplies consist primarily of tubular goods and well equipment to be used in future drilling operations or repair operations and are carried at the lower of cost or market value, on a first-in, first-out basis.
	The following table sets forth the net capitalized costs and associated accumulated DD&A and non-cash impairments relating to the Company’s oil, natural gas and NGL producing activities:
		As of December 31,
		2014				2013
		(in thousands)
	Proved properties	$	390,482			$	485,427
	Wells and related equipment and facilities	1,537,370				2,192,754
	Support equipment and facilities	68,371				177,224
	Materials and supplies	13,069				8,518
	Total proved oil and gas properties	$	2,009,292			$	2,863,923
	Unproved properties	78,898				189,759
	Wells and facilities in progress	69,936				56,674
	Total unproved oil and gas properties, excluded from amortization	$	148,834			$	246,433
	Assets held for sale	9,234				—
	Accumulated depreciation, depletion, amortization and impairment	(427,954		)		(926,173		)
	Total oil and gas properties, net	$	1,739,406			$	2,184,183
	All exploratory wells are evaluated for economic viability within one year of well completion. Exploratory wells that discover potentially economic reserves in areas where a major capital expenditure would be required before production could begin, and where the economic viability of that major capital expenditure depends upon the successful completion of further exploratory work in the area, remain capitalized if the well finds a sufficient quantity of reserves to justify its completion as a producing well and the Company is making sufficient progress assessing the reserves and the economic and operating viability of the project. As of December 31, 2014 and 2013, there were no exploratory well costs that had been capitalized for a period greater than one year since the completion of drilling.
	The Company reviews proved oil and gas properties on a field-by-field basis for impairment on a quarterly basis or whenever events and circumstances indicate that a decline in the recoverability of their carrying value may have occurred. The Company estimates the expected undiscounted future cash flows of its oil and gas properties and compares such undiscounted future cash flows to the carrying amount of the oil and gas properties to determine if the carrying amount is recoverable. If the carrying value of a property exceeds the undiscounted future cash flows, the Company will impair the carrying value to fair value based on an analysis of quantitative and qualitative factors. The Company has no guarantee that the undiscounted future cash flows analysis of its proved property represents the applicable market value. The factors used to determine fair value include, but are not limited to, recent sales prices of comparable properties, the present value of future revenues, net of estimated operating and development costs using estimates of reserves, future commodity pricing, future production estimates, anticipated capital expenditures and various discount rates commensurate with the risk and current market conditions associated with realizing the expected cash flows projected.
	The Company recognized non-cash impairment charges, which were included within impairment, dry hole costs and abandonment expense in the Consolidated Statements of Operations, as follows:
		Year Ended December 31,
		2014				2013				2012
		(in thousands)
	Non-cash impairment of proved oil and gas properties	$	15,761		(1)	$	206,953		(3)	$	—
	Non-cash impairment of unproved oil and gas properties	24,082			(2)	19,598			(3)	37,348		(4)
	Non-cash impairment of inventory	340				—				—
	Dry hole costs	101				1,124				21,012
	Abandonment expense	6,597				10,723				9,509
	Total non-cash impairment, dry hole costs and abandonment expense	$	46,881			$	238,398			$	67,869
	-1	As a result of the Powder River Oil Divestiture (see Note 4), the carrying values of the remaining properties were analyzed relative to their estimated fair market value. As a result, the Company recognized impairment of $14.8 million. These properties were classified as held for sale as of December 31, 2014. The remaining impairment of $1.0 million related to the West Tavaputs Divestiture (see Note 4) based upon a true up of previously estimated carrying value.
	-2	As a result of unfavorable drilling and completion results in the Paradox Basin, the Company recognized an impairment of $11.6 million related to unproved oil and gas properties. In addition, the Company recognized an impairment of $6.1 million related to certain unproved oil and gas properties in the Uinta Basin as a result of no future plans to evaluate certain acreage positions. The Company recognized an impairment of $6.4 million to unproved oil and gas properties as the result of the Powder River Oil Divestiture discussed in (1) above.
	-3	As a result of an analysis of remaining carrying values relative to fair market values resulting from the West Tavaputs Divestiture (see Note 4), $207.0 million and $2.5 million of proved and unproved property impairment, respectively, was incurred during the year ended December 31, 2013. As a result of no future plans to evaluate remaining acreage and estimated market value below carrying value within various exploration projects, an additional $17.1 million of unproved property impairment was incurred during the year ended December 31, 2013.
	-4	As a result of unfavorable natural gas exploratory results, no future plans to evaluate remaining acreage and estimated market value below our carrying value within exploration projects, $37.3 million of unproved property impairment was incurred during the year ended December 31, 2012.
	The provision for DD&A of oil and gas properties is calculated on a field-by-field basis using the unit-of-production method. Natural gas and NGLs are converted to an oil equivalent, Boe, at the standard rate of six Mcf to one Boe and forty-two gallons to one Boe, respectively. Estimated future dismantlement, restoration and abandonment costs are taken into consideration by this calculation.
Environmental Liabilities	Environmental Liabilities. Environmental expenditures that relate to an existing condition caused by past operations and that do not contribute to current or future revenue generation are expensed. Environmental liabilities are accrued when environmental assessments and/or clean-ups are probable, and the costs can be reasonably estimated.
Revenue Recognition	Revenue Recognition. Oil, gas and NGL revenues are recognized when production is sold to a purchaser at a fixed or determinable price, when delivery has occurred and title has transferred, and collectability of the revenue is reasonably assured. The Company uses the sales method to account for gas and NGL imbalances. Under this method, revenues are recorded on the basis of gas and NGLs actually sold by the Company. In addition, the Company records revenues for its share of gas and NGLs sold by other owners that cannot be volumetrically balanced in the future due to insufficient remaining reserves. The Company also reduces revenues for other owners' gas and NGLs sold by the Company that cannot be volumetrically balanced in the future due to insufficient remaining reserves. The Company's remaining over- and under- produced gas and NGLs balancing positions are taken into account in determining the Company's proved oil, gas and NGL reserves. Imbalances at December 31, 2014 and 2013 were not material.
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities. The Company periodically uses derivative financial instruments to achieve a more predictable cash flow from its oil, natural gas and NGL sales by reducing its exposure to price fluctuations. Derivative instruments are recorded at fair market value and are included in the Consolidated Balance Sheets as assets or liabilities.
Income Taxes	Income Taxes. Income taxes are provided for the tax effects of transactions reported in the financial statements and consist of taxes currently payable plus deferred income taxes related to certain income and expenses recognized in different periods for financial and income tax reporting purposes. Deferred income tax assets and liabilities represent the future tax return consequences of those differences, which will either be taxable or deductible when assets are recovered or liabilities are settled. Deferred income taxes also include tax credits and net operating losses that are available to offset future income taxes. Deferred income taxes are measured by applying currently enacted tax rates.
	The Company accounts for uncertainty in income taxes for tax positions taken or expected to be taken in a tax return. Only tax positions that meet the more-likely-than-not recognition threshold are recognized.
Earnings/Loss Per Share	Earnings/Loss Per Share. Basic net income (loss) per common share is calculated by dividing net income (loss) attributable to common stock by the weighted average number of common shares outstanding during each period. Diluted net income (loss) per common share is calculated by dividing net income (loss) attributable to common stock by the weighted average number of common shares outstanding and other dilutive securities. Potentially dilutive securities for the diluted net income per common share calculations consist of nonvested equity shares of common stock, in-the-money outstanding stock options to purchase the Company’s common stock and shares into which the Convertible Notes are convertible. No potential common shares are included in the computation of any diluted per share amount when a net loss exists, as was the case for the year ended December 31, 2013.
	In satisfaction of its obligation upon conversion of the Convertible Notes, the Company may elect to deliver, at its option, cash, shares of its common stock or a combination of cash and shares of its common stock. As of December 31, 2014, the Company expected to settle the remaining Convertible Notes in cash. Therefore, the treasury stock method was used to measure the potentially dilutive impact of shares associated with that remaining conversion feature. The Company has the right at any time with at least 30 days’ notice to call the Convertible Notes and the holders have the right to require the Company to purchase the notes on March 20, 2015, March 20, 2018 and March 20, 2023. The Convertible Notes have not been dilutive since their issuance in March 2008 and, therefore, did not impact the diluted net income per common share calculation for the years ended December 31, 2014 and 2012. The diluted net income per common share excludes the anti-dilutive effect of 1,406,938 and 3,162,436 stock options and nonvested equity shares of common stock for the years ended December 31, 2014 and 2012, respectively.
	The following table sets forth the calculation of basic and diluted net income (loss) per share:
		Year Ended December 31,
		2014				2013				2012
		(in thousands, except per share amounts)
	Net income (loss)	$	15,081			$	(192,733	)		$	582
	Basic weighted-average common shares outstanding in period	48,011				47,497				47,195
	Add dilutive effects of stock options and nonvested equity shares of common stock	425				—				159
	Diluted weighted-average common shares outstanding in period	48,436				47,497				47,354
	Basic net income (loss) per common share	$	0.31			$	(4.06	)		$	0.01
	Diluted net income (loss) per common share	$	0.31			$	(4.06	)		$	0.01
Industry Segment and Geographic Information	Industry Segment and Geographic Information. The Company operates in one industry segment, which is the development and production of crude oil, natural gas and NGLs, and all of the Company’s operations are conducted in the continental United States. Consequently, the Company currently reports as a single industry segment.
New Accounting Pronouncements	New Accounting Pronouncements. In August 2014, the FASB issued ASU 2014-15, Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern. The objective of this update is to provide guidance in GAAP about management's responsibility to evaluate whether there is substantial doubt about an entity's ability to continue as a going concern and to provide related footnote disclosures. ASU 2014-15 is effective for the annual period ending after December 15, 2016, and for annual periods and interim periods thereafter. The standard will be adopted prospectively.
	In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers. The objective of this update is to clarify the principles for recognizing revenue and to develop a common revenue standard. ASU 2014-09 is effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. The Company is currently evaluating the potential impact that the adoption will have on the Company’s disclosures and financial statements.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies - (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Accounts Receivable	Accounts Receivable. Accounts receivable is comprised of the following:
		As of December 31,
		2014				2013
		(in thousands)
	Accrued oil, gas and NGL sales	$	35,099			$	67,583
	Due from joint interest owners	27,937				23,507
	Other (1)	49,187				6,517
	Allowance for doubtful accounts	(14		)		(21		)
	Total accounts receivable	$	112,209			$	97,586
	-1	Other includes a receivable of $47.6 million (including $4.7 million due to another industry partner) related to a settlement agreement with the Department of Interior ("DOI") resulting in the cancellation of certain Cottonwood Gulch natural gas leases during the three months ended December 31, 2014.
Net Capitalized Costs and Associated Accumulated DD&A and Non Cash Impairments	The following table sets forth the net capitalized costs and associated accumulated DD&A and non-cash impairments relating to the Company’s oil, natural gas and NGL producing activities:
		As of December 31,
		2014				2013
		(in thousands)
	Proved properties	$	390,482			$	485,427
	Wells and related equipment and facilities	1,537,370				2,192,754
	Support equipment and facilities	68,371				177,224
	Materials and supplies	13,069				8,518
	Total proved oil and gas properties	$	2,009,292			$	2,863,923
	Unproved properties	78,898				189,759
	Wells and facilities in progress	69,936				56,674
	Total unproved oil and gas properties, excluded from amortization	$	148,834			$	246,433
	Assets held for sale	9,234				—
	Accumulated depreciation, depletion, amortization and impairment	(427,954		)		(926,173		)
	Total oil and gas properties, net	$	1,739,406			$	2,184,183
Non-Cash Impairment Charges, Included within Impairment, Dry Hole Costs and Abandonment Expense in Consolidated Statements of Operations	The Company recognized non-cash impairment charges, which were included within impairment, dry hole costs and abandonment expense in the Consolidated Statements of Operations, as follows:
		Year Ended December 31,
		2014				2013				2012
		(in thousands)
	Non-cash impairment of proved oil and gas properties	$	15,761		(1)	$	206,953		(3)	$	—
	Non-cash impairment of unproved oil and gas properties	24,082			(2)	19,598			(3)	37,348		(4)
	Non-cash impairment of inventory	340				—				—
	Dry hole costs	101				1,124				21,012
	Abandonment expense	6,597				10,723				9,509
	Total non-cash impairment, dry hole costs and abandonment expense	$	46,881			$	238,398			$	67,869
	-1	As a result of the Powder River Oil Divestiture (see Note 4), the carrying values of the remaining properties were analyzed relative to their estimated fair market value. As a result, the Company recognized impairment of $14.8 million. These properties were classified as held for sale as of December 31, 2014. The remaining impairment of $1.0 million related to the West Tavaputs Divestiture (see Note 4) based upon a true up of previously estimated carrying value.
	-2	As a result of unfavorable drilling and completion results in the Paradox Basin, the Company recognized an impairment of $11.6 million related to unproved oil and gas properties. In addition, the Company recognized an impairment of $6.1 million related to certain unproved oil and gas properties in the Uinta Basin as a result of no future plans to evaluate certain acreage positions. The Company recognized an impairment of $6.4 million to unproved oil and gas properties as the result of the Powder River Oil Divestiture discussed in (1) above.
	-3	As a result of an analysis of remaining carrying values relative to fair market values resulting from the West Tavaputs Divestiture (see Note 4), $207.0 million and $2.5 million of proved and unproved property impairment, respectively, was incurred during the year ended December 31, 2013. As a result of no future plans to evaluate remaining acreage and estimated market value below carrying value within various exploration projects, an additional $17.1 million of unproved property impairment was incurred during the year ended December 31, 2013.
	-4	As a result of unfavorable natural gas exploratory results, no future plans to evaluate remaining acreage and estimated market value below our carrying value within exploration projects, $37.3 million of unproved property impairment was incurred during the year ended December 31, 2012.
Accounts Payable and Accrued Liabilities	Accounts Payable and Accrued Liabilities. Accounts payable and accrued liabilities are comprised of the following:
		As of December 31,
		2014				2013
		(in thousands)
	Accrued drilling, completion and facility costs	$	68,124			$	54,750
	Accrued lease operating, gathering, transportation and processing expenses	12,526				17,317
	Accrued general and administrative expenses	8,482				14,605
	Accrued interest payable	14,284				14,860
	Accrued payables for property sales	16,296				2,905
	Trade payables and other	6,540				11,491
	Total accounts payable and accrued liabilities	$	126,252			$	115,928
Calculation of Basic and Diluted Earnings Per Share	The following table sets forth the calculation of basic and diluted net income (loss) per share:
		Year Ended December 31,
		2014				2013				2012
		(in thousands, except per share amounts)
	Net income (loss)	$	15,081			$	(192,733	)		$	582
	Basic weighted-average common shares outstanding in period	48,011				47,497				47,195
	Add dilutive effects of stock options and nonvested equity shares of common stock	425				—				159
	Diluted weighted-average common shares outstanding in period	48,436				47,497				47,354
	Basic net income (loss) per common share	$	0.31			$	(4.06	)		$	0.01
	Diluted net income (loss) per common share	$	0.31			$	(4.06	)		$	0.01

Supplemental_Disclosures_of_Ca1

Supplemental Disclosures of Cash Flow Information (Tables)	12 Months Ended
	Dec. 31, 2014
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Supplemental cash flow information is as follows:
		Year Ended December 31,
		2014			2013			2012
		(in thousands)
	Cash paid for interest, net of amount capitalized	$	65,935		$	94,205		$	83,718
	Cash paid for income taxes	1			1,163			10
	Supplemental disclosures of non-cash investing and financing activities:
	Accrued receivables - oil and gas properties (1)	42,872			—			—
	Accrued liabilities - oil and gas properties	72,297			75,340			49,598
	Change in asset retirement obligations, net of disposals	(22,740		)	(6,996		)	(25,236		)
	Retirement of treasury stock	2,684			1,778			2,513
	Fair value of properties exchanged in non-cash transactions	77,078			—			—
	Transfer of lease financing obligation	36,075			45,190			—
	-1	Includes a receivable of $42.9 million related to a settlement agreement with the Department of Interior ("DOI") resulting in the cancellation of certain Cottonwood Gulch natural gas leases in 2014.

Divestitures_and_Assets_Held_f1

Divestitures and Assets Held for Sale - (Tables)	12 Months Ended
	Dec. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]
Disposal Groups Excluding Discontinued Operations Disclosure [Table Text Block]	The carrying amounts by major asset class within the disposal group for the Piceance Divestiture are summarized below (in thousands):
	Assets:
	Proved properties	$	1,320,745
	Furniture, equipment and other	4,907
	Accumulated depreciation, depletion, amortization and impairment	(688,864		)
	Total assets	$	636,788
	Liabilities:
	Asset retirement obligation	$	22,448
	Lease financing obligation	36,075
	Other liabilities	84
	Total liabilities	$	58,607
	Net assets	$	578,181

LongTerm_Debt_Tables

Long-Term Debt - (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Outstanding Debt	The Company’s outstanding debt is summarized below:
			As of December 31, 2014								As of December 31, 2013
		Maturity Date	Principal			Unamortized			Carrying		Principal		Unamortized		Carrying
						Discount			Amount				Discount		Amount
			(in thousands)
	Amended Credit Facility (1)	October 31, 2016	$	—		$	—		$	—	$	115,000	$	—	$	115,000
	Convertible Notes (2)	March 15, 2028 (3)	25,344			—			25,344		25,344		—		25,344
	7.625% Senior Notes (4)	October 1, 2019	400,000			—			400,000		400,000		—		400,000
	7.0% Senior Notes (5)	October 15, 2022	400,000			—			400,000		400,000		—		400,000
	Lease Financing Obligation (6)	August 10, 2020	3,648			—			3,648		43,329		—		43,329
	Total Debt		$	828,992		$	—		$	828,992	$	983,673	$	—	$	983,673
	Less: Current Portion of Long-Term Debt (7)(8)		25,770			—			25,770		4,591		—		4,591
	Total Long-Term Debt		$	803,222		$	—		$	803,222	$	979,082	$	—	$	979,082
	-1	The recorded value of the Amended Credit Facility approximates its fair value due to its floating rate structure.
	-2	The aggregate estimated fair value of the Convertible Notes was approximately $25.1 million as of December 31, 2014 and 2013, based on reported market trades of these instruments.
	-3	The Company has the right at any time, with at least 30 days’ notice, to call the Convertible Notes, and the holders have the right to require the Company to purchase the notes on each of March 20, 2015, March 20, 2018 and March 20, 2023.
	-4	The aggregate estimated fair value of the 7.625% Senior Notes was approximately $359.8 million and $430.2 million as of December 31, 2014 and 2013, respectively, based on reported market trades of these instruments.
	-5	The aggregate estimated fair value of the 7.0% Senior Notes was approximately $366.0 million and $417.0 million as of December 31, 2014 and 2013, respectively, based on reported market trades of these instruments.
	-6	The aggregate estimated fair value of the Lease Financing Obligation was approximately $3.5 million and $41.7 million as of December 31, 2014 and 2013, respectively. The decrease in estimated fair value is primarily related to the sale of equipment in the Piceance Divestiture. As there is no active public market for the Lease Financing Obligation, the aggregate estimated fair value was based on market-based parameters of comparable term secured financing instruments.
	-7	The current portion of long-term debt as of December 31, 2014 includes the current portion of the Lease Financing Obligation and the principal amount of the Convertible Notes. The Company classified the Convertible Notes as a current obligation as of December 31, 2014 as the holders may require us to purchase their Convertible Notes for cash on March 20, 2015.
	-8	The current portion of long-term debt as of December 31, 2013 includes the current portion of the Lease Financing Obligation.
Cash and Non-Cash Portion of Interest Expense Related to Long Term Debt	The following table summarizes, for the periods indicated, the cash or accrued portion of interest expense related to the Amended Credit Facility, 9.875% Senior Notes that were redeemed in full on July 15, 2013, Convertible Notes, 7.625% Senior Notes, 7.0% Senior Notes and the Lease Financing Obligation along with the non-cash portion resulting from the amortization of the debt discount and transaction costs through interest expense:
		As of December 31,
		2014			2013			2012
		(in thousands)
	Amended Credit Facility (1)
	Cash interest	$	4,837		$	6,802		$	5,652
	Non-cash interest	2,342			2,342			2,342
	9.875% Senior Notes (2)
	Cash interest	$	—		$	13,373		$	24,688
	Non-cash interest	—			1,361			2,571
	Convertible Notes (3)
	Cash interest	$	1,264		$	1,267		$	2,909
	Non-cash interest	5			6			1,771
	7.625% Senior Notes (4)
	Cash interest	$	30,500		$	30,500		$	30,500
	Non-cash interest	1,090			1,070			1,066
	7.0% Senior Notes (5)
	Cash interest	$	28,000		$	28,000		$	22,400
	Non-cash interest	814			795			659
	Lease Financing Obligation (6)
	Cash interest	$	638		$	2,852		$	1,353
	Non-cash interest	12			30			15
	-1	Cash interest includes amounts related to interest and commitment fees paid on the Amended Credit Facility and participation and fronting fees paid on the letter of credit.
	-2	The stated interest rate for the 9.875% Senior Notes was 9.875% per annum with an effective interest rate of 11.2% per annum. The Company redeemed the 9.875% Senior Notes in full on July 15, 2013.
	-3	The stated interest rate for the Convertible Notes is 5% per annum. The effective interest rate of the Convertible Notes includes amortization of the debt discount, which represented the fair value of the equity conversion feature at the time of issue. The stated interest rate of 5% on the Convertible Notes is the effective interest rate of the $25.3 million remaining principal balance, as the related debt discount was fully amortized as of March 31, 2012.
	-4	The stated interest rate for the 7.625% Senior Notes is 7.625% per annum with an effective interest rate of 8.0% per annum.
	-5	The stated interest rate for the 7.0% Senior Notes is 7.0% per annum with an effective interest rate of 7.2% per annum.
	-6	The effective interest rate for the Lease Financing Obligation is 3.3% per annum. The decrease in cash interest from $2.9 million to $0.6 million for the years ended December 31, 2013 and 2014, respectively, is due to the West Tavaputs and Piceance Divestitures.

Asset_Retirement_Obligations_T

Asset Retirement Obligations - (Tables)	12 Months Ended
	Dec. 31, 2014
Asset Retirement Obligation Disclosure [Abstract]
Schedule of Asset Retirement Obligations	A reconciliation of the Company’s asset retirement obligations for the year ended December 31, 2014, 2013 and 2012 is as follows:
		Year Ended December 31,
		2014			2013			2012
		(in thousands)
	Beginning of period	$	43,005		$	47,616		$	69,302
	Liabilities incurred	4,027			2,359			4,046
	Liabilities settled	(6,283		)	(1,096		)	(871		)
	Disposition of properties	(23,722		)	(13,543		)	(33,560		)
	Accretion expense	2,587			3,481			4,421
	Revisions to estimate	3,238			4,188			4,278
	End of period	$	22,852		$	43,005		$	47,616
	Less: Liabilities associated with properties held for sale	146			—			—
	Less: Current asset retirement obligations	1,114			3,805			1,566
	Long-term asset retirement obligations	$	21,592		$	39,200		$	46,050

Fair_Value_Measurements_Tables

Fair Value Measurements - (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value, Balance Sheet Grouping	The following tables set forth by level within the fair value hierarchy the Company’s financial assets and financial liabilities that were measured at fair value on a recurring basis. Assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of assets and liabilities and their placement within the fair value hierarchy levels.
		As of December 31, 2014
		Level 1		Level 2		Level 3		Total
		(in thousands)
	Assets
	Deferred Compensation Plan	$	1,069	$	—	$	—	$	1,069
	Cash Equivalents - Money Market Funds	75,066		—		—		75,066
	Commodity Derivatives	—		195,176		—		195,176
	Liabilities
	Commodity Derivatives	$	—	$	200	$	—	$	200
		As of December 31, 2013
		Level 1		Level 2		Level 3		Total
		(in thousands)
	Assets
	Deferred Compensation Plan	$	941	$	—	$	—	$	941
	Cash Equivalents - Money Market Funds	53		—		—		53
	Commodity Derivatives	—		11,483		—		11,483
	Liabilities
	Commodity Derivatives	$	—	$	14,771	$	—	$	14,771
Schedule of Assets and Liabilities Measured on Non-recurring Basis
		Net Carrying Value as of December 31, 2014		Impairment for the Year Ended December 31, 2014
				Level 1		Level 2		Level 3
		(in thousands)
	Proved property (1)(2)	$	1,588,038	$	—	$	—	$	15,761
	Unproved property (1)(2)	151,368		—		—		24,082
	-1	See Note 2 for additional details on impairment expense recognized.
	-2	Includes $6.7 million of net proved property and $2.5 million of net unproved property associated with properties held for sale as of December 31, 2014.
	The Company utilizes fair value on a non-recurring basis to perform impairment tests on its property and equipment when required. During the year ended December 31, 2013, the Company recorded impairment charges of $226.6 million on proved and unproved oil and gas properties. Included in the total impairment charge of $226.6 million was $209.5 million of impairment charges related to the West Tavaputs area of the Uinta Basin for which the Company utilized third party purchase offers as the basis for determining fair value. This property was sold in December 2013. The inputs used to determine such fair value for other non-recurring impairment tests are primarily based upon internally developed cash flow models as well as available external market data and would generally be classified within Level 3.
		Net Carrying Value as of December 31, 2013		Impairment for the Year Ended December 31, 2013
				Level 1		Level 2		Level 3
		(in thousands)
	Proved property (1)	$	1,937,913	$	—	$	—	$	206,953
	Unproved property (1)	246,270		—		—		19,598
	-1	See Note 2 for additional details on impairment expense recognized.

Derivative_Instruments_Tables

Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Value Amounts of Derivative Instruments	The following table summarizes the location, as well as the gross and net fair value amounts of all derivative instruments presented on the Consolidated Balance Sheets as of the dates indicated.
		As of December 31, 2014
	Balance Sheet	Gross Amounts of				Gross Amounts				Net Amounts of Assets
		Recognized Assets				Offset in the Balance				Presented in the Balance
						Sheet				Sheet
						(in thousands)
	Derivative assets (current)	$	145,426			$	(200	)	(1)	$	145,226
	Derivative assets (noncurrent)	49,750				—			(1)	49,750
	Total derivative assets	$	195,176			$	(200	)		$	194,976
		Gross Amounts of				Gross Amounts				Net Amounts of Liabilities
		Recognized				Offset in the Balance				Presented in the Balance
		Liabilities				Sheet				Sheet
						(in thousands)
	Derivative liabilities	$	(200	)		$	200		(2)	$	—
	Derivatives and other noncurrent liabilities	—				—			(2)	—			(3)
	Total derivative liabilities	$	(200	)		$	200			$	—
		As of December 31, 2013
	Balance Sheet	Gross Amounts of				Gross Amounts				Net Amounts of Assets
		Recognized Assets				Offset in the Balance				Presented in the Balance
						Sheet				Sheet
						(in thousands)
	Derivative assets (current)	$	8,259			$	(8,086	)	(1)	$	173
	Derivative assets (noncurrent)	3,224				(685		)	(1)	2,539
	Total derivative assets	$	11,483			$	(8,771	)		$	2,712
		Gross Amounts of				Gross Amounts				Net Amounts of Liabilities
		Recognized				Offset in the Balance				Presented in the Balance
		Liabilities				Sheet				Sheet
						(in thousands)
	Derivative liabilities	$	(14,074	)		$	8,086		(2)	$	(5,988	)
	Derivatives and other noncurrent liabilities	(697		)		685			(2)	(12		)	(3)
	Total derivative liabilities	$	(14,771	)		$	8,771			$	(6,000	)
	-1	Amounts are netted against derivative asset balances with the same counterparty, and therefore, are presented as a net asset on the Consolidated Balance Sheets.
	-2	Amounts are netted against derivative liability balances with the same counterparty, and therefore are presented as a net liability on the Consolidated Balance Sheets.
	-3	As of December 31, 2014 and 2013, this line item on the Consolidated Balance Sheets includes $3.0 million and $3.5 million of other noncurrent liabilities, respectively.
Cash Flow Hedge Gains and Losses	The following table summarizes the cash flow hedge gains, net of tax, and their locations on the Consolidated Balance Sheets and Consolidated Statements of Operations for the periods indicated:
		Derivatives Qualifying as		Year Ended December 31,
		Cash Flow Hedges		2014				2013				2012
				(in thousands)
	Amount of Gain (Loss) Recognized in AOCI (1)	Commodity Hedges		$	—			$	—			$	—
	Amount of Gain (Loss) Reclassified from AOCI into Income (net of tax) (1)(2)	Commodity Hedges		$	669			$	4,663			$	50,712
	Amount of Gain (Loss) Recognized in Income on Ineffective Hedges	Commodity Hedges		$	—			$	—			$	—
	-1	Presented net of income tax expense of $0.4 million, $2.8 million and $30.5 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	-2	Gains reclassified from AOCI into income are included in the oil, gas and NGL production revenues in the Consolidated Statements of Operations.
Financial Instruments for Hedging Volumes	As of December 31, 2014, the Company had financial instruments in place to hedge the following volumes for the periods indicated:
		Year Ending December 31,
		2015			2016			2017
	Oil (Bbls)	4,022,600			1,737,000			365,000
	Natural Gas (MMbtu)	7,207,000			1,830,000			—
Realized and Unrealized Gains and Losses on Commodity Derivative Instruments	The table below summarizes the commodity derivative gains and losses the Company recognized related to its oil, gas and NGL derivative instruments for the periods indicated:
		Year Ended December 31,
		2014				2013				2012
		(in thousands)
	Commodity derivative settlements on derivatives designated as cash flow hedges (1)	$	1,070			$	7,463			$	81,166
	Total commodity derivative gain (loss) (2)	197,447				(23,068		)		72,759
	-1	Included in oil, gas and NGL production revenues in the Consolidated Statements of Operations.
	-2	Included in commodity derivative gain (loss) in the Consolidated Statements of Operations.

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Expense for Income Taxes	The expense for income taxes consisted of the following for the periods indicated:
		Year Ended December 31,
		2014			2013			2012
		(in thousands)
	Current:
	Federal	$	1,220		$	(1,233	)	$	966
	State	44			(352		)	886
	Foreign	1			2			1
	Deferred:
	Federal	10,246			(107,300		)	100
	State	6,398			(9,750		)	(317		)
	Total	$	17,909		$	(118,633	)	$	1,636
Reconciliation of Actual Income Tax Expense	Income tax expense differed from the amounts computed by applying the U.S. federal income tax rate of 35% to pretax income from continuing operations as a result of the following:
		Year Ended December 31,
		2014			2013			2012
		(in thousands)
	Income tax expense at the federal statutory rate	$	11,546		$	(108,978	)	$	777
	State income taxes, net of federal tax effect	932			(6,702		)	(269		)
	Incentive stock compensation	199			678			635
	Nondeductible political contributions and lobbying costs	108			96			271
	Nondeductible officer compensation	229			138			—
	Other permanent items	89			52			26
	Deferred tax related to the changes in overall state tax rates	5,230			(3,851		)	310
	Other, net	(424		)	(66		)	(114		)
	Income tax expense (benefit)	$	17,909		$	(118,633	)	$	1,636
Components of Deferred Tax Assets and Deferred Tax Liabilities	The tax effects of temporary differences that give rise to significant components of the deferred tax assets and deferred tax liabilities at December 31, 2014 and 2013 are presented below:
		As of December 31,
		2014			2013
		(in thousands)
	Current:
	Deferred tax assets (liabilities):
	Derivative instruments	$	(54,933	)	$	(89	)
	Accrued expenses	229			400
	Bad debt expense	5			8
	Prepaid expenses	(702		)	(648		)
	Other	(17		)	130
	Total current deferred tax assets (liabilities)	$	(55,418	)	$	(199	)
	Long-term:
	Deferred tax assets:
	Net operating loss carryforward	$	56,529		$	75,511
	Deferred offering costs	1,182			1,243
	Stock-based compensation	15,767			14,200
	Deferred rent	787			962
	Minimum tax credit carryforward	1,690			688
	Deferred compensation	1,062			999
	State tax credit carryforwards	5,110			5,871
	Production payment loan	—			3,839
	Financing obligation	1,586			16,227
	Other	250			222
	Less: Valuation allowance	(5,110		)	(5,871		)
	Total long-term deferred tax assets	78,853			113,891
	Deferred tax liabilities:
	Oil and gas properties	(182,385		)	(276,523		)
	Long-term derivative instruments	(18,818		)	1,306
	Total long-term deferred tax liabilities	(201,203		)	(275,217		)
	Net long-term deferred tax liabilities	$	(122,350	)	$	(161,326	)

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Schedule of Stockholders Equity	The following table reflects the activity in the Company’s common and treasury stock for the periods indicated:
		Year Ended December 31,
		2014			2013			2012
	Common Stock Outstanding:
	Shares at beginning of period	49,152,448			48,150,475			47,809,903
	Exercise of common stock options	7,926			259,699			36,560
	Shares issued for 401(k) plan	36,533			47,235			41,415
	Shares issued for directors' fees	44,551			52,081			12,973
	Shares issued for nonvested equity shares of common stock	857,870			1,081,259			454,666
	Shares retired or forfeited	(572,691	)		(438,301	)		(205,042	)
	Shares at end of period	49,526,637			49,152,448			48,150,475
	Treasury Stock:
	Shares at beginning of period	—			—			—
	Treasury stock acquired	116,813			96,880			92,393
	Treasury stock retired	(116,813	)		(96,880	)		(92,393	)
	Shares at end of period	—			—			—
Schedule of Accumulated Other Comprehensive Income	The components of accumulated other comprehensive income and related tax effects for the years ended December 31, 2012, 2013 and 2014 were as follows:
		Gross				Tax Effect				Net of Tax
		(in thousands)
	Accumulated other comprehensive income — December 31, 2011	$	89,714			$	(33,670	)		$	56,044
	Reclassification adjustment for realized gains on hedges included in net income	(81,170		)		30,458				(50,712		)
	Accumulated other comprehensive income — December 31, 2012	$	8,544			$	(3,212	)		$	5,332
	Reclassification adjustment for realized gains on hedges included in net income	(7,465		)		2,802				(4,663		)
	Accumulated other comprehensive income — December 31, 2013	$	1,079			$	(410	)		$	669
	Reclassification adjustment for realized gains on hedges included in net income	(1,079		)		410				(669		)
	Accumulated other comprehensive income — December 31, 2014	$	—			$	—			$	—

Equity_Incentive_Compensation_1

Equity Incentive Compensation Plans and Other Employee Benefits (Tables)	12 Months Ended
	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-Cash Stock-Based Compensation Cost Related to Equity Awards	The following table presents the non-cash stock-based compensation related to equity awards for the periods indicated:
		Year Ended December 31,
		2014				2013				2012
		(in thousands)
	Common stock options	$	2,073			$	4,696			$	7,189
	Nonvested equity common stock	6,845				7,492				7,394
	Nonvested equity common stock units (1)	1,065				1,272				708
	Nonvested performance-based equity	990				2,174				1,079
	Total	$	10,973			$	15,634			$	16,370
	-1	Includes non-cash stock-based compensation related to director fees of $0.1 million, $0.4 million and $0.2 million for the years ended December 31, 2014, 2013 and 2012, respectively.
Fair Value Assumptions and Methodology	The Company estimated a 4% to 10% annual compounded forfeiture rate for the year 2012 based on historical employee turnover and actual forfeitures. The Company did not grant any share-based option awards during the years 2014 or 2013.
			2012
	Weighted average volatility		51	%
	Expected dividend yield		—	%
	Weighted average expected term (in years)		4.3
	Weighted average risk-free rate		1.8	%
Summary of Share-Based Option Activity	A summary of share-based option activity under all the Company's plans as of December 31, 2014, and changes during the year then ended, is presented below:
		Shares			Weighted Average				Weighted Average		Aggregate
					Exercise Price				Remaining		Intrinsic Value
									Contractual Term
									(in years)
	Outstanding at January 1, 2014	1,748,696			$	32.66
	Granted	—			$	—
	Exercised	(7,926	)		$	18.22
	Forfeited or expired	(401,405	)		$	33.56
	Outstanding at December 31, 2014	1,339,365			$	32.47			1.37		$	—
	Vested and expected to vest, at December 31, 2014 through the life of the options	1,332,062			$	30.33			1.92		$	—
	Vested and exercisable at December 31, 2014	1,151,004			$	33.05			1.6		$	—
Summary of Nonvested Equity Shares of Common Stock	A summary of the Company’s nonvested equity shares of common stock as of December 31, 2014, 2013 and 2012, and changes during the years then ended, is presented below:
		Year Ended December 31,
		2014							2013					2012
		Shares			Weighted				Shares			Weighted		Shares		Weighted
					Average							Average				Average
					Grant Date							Grant Date				Grant Date
					Fair							Fair				Fair
					Value							Value				Value
	Outstanding at January 1,	756,118			$	22.17			579,188			$	31.02	639,628		$	35.12
	Granted	542,209			$	22			630,715			$	17.98	274,679		$	25.62
	Vested	(292,168	)		$	24.05			(270,482	)		$	29.82	(241,736	)	$	34.61
	Forfeited or expired	(213,095	)		$	21.99			(183,303	)		$	24.87	(93,383	)	$	33.39
	Outstanding at December 31,	793,064			$	21.47			756,118			$	22.17	579,188		$	31.02
Summary of Nonvested Performance-Based Equity Shares of Common Stock	A summary of the Company's non-vested performance-based equity shares of common stock as of December 31, 2014, 2013 and 2012, and changes during the years then ended, is presented below:
		Year Ended December 31,
		2014							2013					2012
		Shares			Weighted				Shares			Weighted		Shares		Weighted
					Average							Average				Average
					Grant Date							Grant Date				Grant Date
					Fair							Fair				Fair
					Value							Value				Value
	Outstanding at January 1,	584,032			$	19.8			291,606			$	26.85	195,630		$	33.36
	Vested	(42,833	)		$	19.51			—			$	—	(64,745	)	$	39.9
	Modified, performance goals revised (1)	—			$	—			(108,933	)		$	27.75	(121,191	)	$	39.9
	Modified, performance goals revised (1)	—			$	—			108,933			$	18.18	121,191		$	27.75
	Granted	315,661			$	23.86			450,544			$	19.99	179,987		$	27.57
	Forfeited or expired	(242,783	)		$	22.13			(158,118	)		$	22.52	(19,266	)	$	33.82
	Outstanding at December 31,	614,077			$	19.62			584,032			$	19.8	291,606		$	26.85
	-1	As the Compensation Committee approved new performance metrics for the vesting of performance shares in the upcoming year, a new grant date was then created for any unvested awards that were granted in previous years, and a new fair value was established for financial reporting purposes.
Directors Fees	A summary of the Company's directors' fees and equity-based compensation for the years ended December 31, 2014, 2013 and 2012 is presented below:
		Year Ended December 31,
		2014				2013				2012
	Director fees (shares)	3,928				16,151				12,973
	Stock-based compensation (in thousands)	$	75			$	351			$	276
Deferred Compensation Liability	The table below summarizes the activity in the plan during the years ended December 31, 2014 and 2013, and the Company’s ending deferred compensation liability as of December 31, 2014 and 2013:
		Year Ended December 31,
		2014				2013
		(in thousands)
	Beginning deferred compensation liability balance	$	941			$	966
	Employee contributions	441				206
	Company matching contributions	160				115
	Distributions	(503		)		(441		)
	Participant earnings (losses)	30				95
	Ending deferred compensation liability balance	$	1,069			$	941
	Amount to be paid within one year	$	220			$	451
	Remaining balance to be paid beyond one year	$	849			$	490
Deferred Compensation Investment Assets	The following table represents the Company's activity in the investment assets held in the rabbi trust during the years ended December 31, 2014 and 2013:
		Year Ended December 31,
		2014				2013
		(in thousands)
	Beginning investment balance	$	941			$	966
	Investment purchases	601				321
	Distributions	(503		)		(441		)
	Earnings (losses)	30				95
	Ending investment balance	$	1,069			$	941
Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of Nonvested Equity Shares of Common Stock	A summary of the Company’s nonvested equity share units of common stock as of December 31, 2014, 2013 and 2012, and changes during the years then ended, is presented in the table below:
		Year Ended December 31,
		2014							2013					2012
		Shares			Weighted				Shares			Weighted		Shares		Weighted
					Average							Average				Average
					Grant Date							Grant Date Fair				Grant Date Fair
					Fair							Value				Value
					Value
	Outstanding at January 1,	55,778			$	19.35			49,185			$	18.5	—		$	—
	Granted	45,928			$	24.49			56,464			$	22.33	58,983		$	18.83
	Vested	(46,761	)		$	22.25			(49,871	)		$	18.96	(9,798	)	$	20.51
	Forfeited or expired	—			$	—			—			$	—	—		$	—
	Outstanding at December 31,	54,945			$	23.84			55,778			$	19.35	49,185		$	18.5

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Schedule of Aggregate Undiscounted Minimum Future Lease Payments	Lease Financing Obligation. The Company has a Lease Financing Obligation with Bank of America Leasing & Capital, LLC as the lead bank as discussed in Note 5. The aggregate undiscounted minimum future lease payments, including both principal and interest components, are presented below:
		As of December 31, 2014
		(in thousands)
	2015	$	537
	2016	537
	2017	537
	2018	537
	2019	1,826
	Thereafter	—
	Total	$	3,974
Gross Future Minimum Transportation Demand and Firm Processing Charges	The Company entered into two firm transportation contracts to provide capacity on natural gas pipeline systems. The remaining term on these contracts is six years. The contracts require the Company to pay transportation charges regardless of the amount of pipeline capacity utilized by the Company. Beginning October 1, 2014, these transportation costs are included in unused commitments expense in the Consolidated Statements of Operations. As a result of the divestitures discussed in Note 4, the Company will likely not utilize the firm capacity on the natural gas pipelines.
	The amounts in the table below represent the Company's future minimum transportation charges.
		As of December 31, 2014
		(in thousands)
	2015	$	17,742
	2016	18,692
	2017	18,692
	2018	18,692
	2019	18,692
	Thereafter	29,595
	Total	$	122,105
Future Minimum Annual Payments Under Drilling, Lease and Other Agreements	Future minimum annual payments under lease and other agreements are as follows:
		As of December 31, 2014
		(in thousands)
	2015	$	4,204
	2016	2,838
	2017	2,690
	2018	2,525
	2019	634
	Thereafter	—
	Total	$	12,891

Guarantor_Subsidiaries_Tables

Guarantor Subsidiaries (Tables)	12 Months Ended
	Dec. 31, 2014
Text Block [Abstract]
Schedule of Condensed Consolidating Balance Sheets	Condensed Consolidating Balance Sheets
		As of December 31, 2014
		Parent			Guarantor			Intercompany			Consolidated
		Issuer			Subsidiaries			Eliminations
		(in thousands)
	Assets:
	Current assets	$	426,103		$	2		$	—		$	426,105
	Property and equipment, net	1,672,513			80,608			—			1,753,121
	Intercompany receivable (payable)	59,592			(59,592		)	—			—
	Investment in subsidiaries	18,647			—			(18,647		)	—
	Noncurrent assets	65,258			—			—			65,258
	Total assets	$	2,242,113		$	21,018		$	(18,647	)	$	2,244,484
	Liabilities and Stockholders’ Equity:
	Current liabilities	$	263,649		$	1,038		$	—		$	264,687
	Long-term debt	803,222			—			—			803,222
	Deferred income taxes	122,350			—			—			122,350
	Other noncurrent liabilities	23,404			1,333			—			24,737
	Stockholders’ equity	1,029,488			18,647			(18,647		)	1,029,488
	Total liabilities and stockholders’ equity	$	2,242,113		$	21,018		$	(18,647	)	$	2,244,484
		As of December 31, 2013
		Parent			Guarantor			Intercompany			Consolidated
		Issuer			Subsidiaries			Eliminations
		(in thousands)
	Assets:
	Current assets	$	154,986		$	2,261		$	—		$	157,247
	Property and equipment, net	2,127,624			74,872			—			2,202,496
	Intercompany receivable (payable)	59,076			(59,076		)	—			—
	Investment in subsidiaries	12,063			—			(12,063		)	—
	Noncurrent assets	21,770			—			—			21,770
	Total assets	$	2,375,519		$	18,057		$	(12,063	)	$	2,381,513
	Liabilities and Stockholders’ Equity:
	Current liabilities	$	192,106		$	613		$	—		$	192,719
	Long-term debt	979,082			—			—			979,082
	Deferred income taxes	158,071			3,255			—			161,326
	Other noncurrent liabilities	40,542			2,126			—			42,668
	Stockholders’ equity	1,005,718			12,063			(12,063		)	1,005,718
	Total liabilities and stockholders’ equity	$	2,375,519		$	18,057		$	(12,063	)	$	2,381,513
Schedule of Condensed Consolidating Statements of Operations	Condensed Consolidating Statements of Operations
		Year Ended December 31, 2014
		Parent			Guarantor			Intercompany			Consolidated
		Issuer			Subsidiaries			Eliminations
		(in thousands)
	Operating and other revenues	$	447,907		$	24,384		$	—		$	472,291
	Operating expenses	(497,258		)	(17,800		)	—			(515,058		)
	General and administrative	(53,361		)	—			—			(53,361		)
	Interest income and other income (expense)	129,118			—			—			129,118
	Income (loss) before income taxes and equity in earnings (loss) of subsidiaries	26,406			6,584			—			32,990
	Provision for income taxes	(17,909		)	—			—			(17,909		)
	Equity in earnings (loss) of subsidiaries	6,584			—			(6,584		)	—
	Net income (loss)	$	15,081		$	6,584		$	(6,584	)	$	15,081
		Year Ended December 31, 2013
		Parent			Guarantor			Intercompany			Consolidated
		Issuer			Subsidiaries			Eliminations
		(in thousands)
	Operating and other revenues	$	538,932		$	29,161		$	—		$	568,093
	Operating expenses	(655,219		)	(27,949		)	—			(683,168		)
	General and administrative	(64,902		)	—			—			(64,902		)
	Interest income and other income (expense)	(131,389		)	—			—			(131,389		)
	Income (loss) before income taxes and equity in earnings (loss) of subsidiaries	(312,578		)	1,212			—			(311,366		)
	Provision for income taxes	118,633			—			—			118,633
	Equity in earnings (loss) of subsidiaries	1,212			—			(1,212		)	—
	Net income (loss)	$	(192,733	)	$	1,212		$	(1,212	)	$	(192,733	)
		Year Ended December 31, 2012
		Parent			Guarantor			Intercompany			Consolidated
		Issuer			Subsidiaries			Eliminations
		(in thousands)
	Operating and other revenues	$	683,319		$	16,876		$	—		$	700,195
	Operating expenses	(599,215		)	(9,105		)	—			(608,320		)
	General and administrative	(68,666		)	—			—			(68,666		)
	Interest and other income (expense)	(20,991		)	—			—			(20,991		)
	Income (loss) before income taxes and equity in earnings (loss) of subsidiaries	(5,553		)	7,771			—			2,218
	Provision for income taxes	(1,636		)	—			—			(1,636		)
	Equity in earnings (loss) of subsidiaries	7,771			—			(7,771		)	—
	Net income (loss)	$	582		$	7,771		$	(7,771	)	$	582
Schedule of Condensed Consolidating Statements of Comprehensive Income	Condensed Consolidating Statements of Comprehensive Income (Loss)
		Year Ended December 31, 2014
		Parent			Guarantor			Intercompany			Consolidated
		Issuer			Subsidiaries			Eliminations
		(in thousands)
	Net Income (Loss)	$	15,081		$	6,584		$	(6,584	)	$	15,081
	Other Comprehensive Income (Loss), net of tax:
	Effect of derivative financial instruments	(669		)	—			—			(669		)
	Other comprehensive loss	(669		)	—			—			(669		)
	Comprehensive Income (Loss)	$	14,412		$	6,584		$	(6,584	)	$	14,412
		Year Ended December 31, 2013
		Parent			Guarantor			Intercompany			Consolidated
		Issuer			Subsidiaries			Eliminations
		(in thousands)
	Net Income (Loss)	$	(192,733	)	$	1,212		$	(1,212	)	$	(192,733	)
	Other Comprehensive Income (Loss), net of tax:
	Effect of derivative financial instruments	(4,663		)	—			—			(4,663		)
	Other comprehensive loss	(4,663		)	—			—			(4,663		)
	Comprehensive Income (Loss)	$	(197,396	)	$	1,212		$	(1,212	)	$	(197,396	)
		Year Ended December 31, 2012
		Parent			Guarantor			Intercompany			Consolidated
		Issuer			Subsidiaries			Eliminations
		(in thousands)
	Net Income (Loss)	$	582		$	7,771		$	(7,771	)	$	582
	Other Comprehensive Income (Loss), net of tax:
	Effect of derivative financial instruments	(50,712		)	—			—			(50,712		)
	Other comprehensive loss	(50,712		)	—			—			(50,712		)
	Comprehensive Income (Loss)	$	(50,130	)	$	7,771		$	(7,771	)	$	(50,130	)
Schedule of Condensed Consolidating Statements of Cash Flows	Condensed Consolidating Statements of Cash Flows
		Year Ended December 31, 2014
		Parent			Guarantor			Intercompany			Consolidated
		Issuer			Subsidiaries			Eliminations
		(in thousands)
	Cash flows from operating activities	$	241,628		$	20,089		$	—		$	261,717
	Cash flows from investing activities:
	Additions to oil and gas properties, including acquisitions	(562,141		)	(18,802		)	—			(580,943		)
	Additions to furniture, fixtures and other	(3,658		)	—			—			(3,658		)
	Proceeds from sale of properties and other investing activities	553,477			1,819			—			555,296
	Intercompany transfers	3,156			—			(3,156		)	—
	Cash flows from financing activities:
	Proceeds from debt	165,000			—			—			165,000
	Principal and redemption premium payments on debt	(283,546		)	—			—			(283,546		)
	Intercompany transfers	—			(3,156		)	3,156			—
	Other financing activities	(2,557		)	—			—			(2,557		)
	Change in cash and cash equivalents	111,359			(50		)	—			111,309
	Beginning cash and cash equivalents	54,545			50			—			54,595
	Ending cash and cash equivalents	$	165,904		$	—		$	—		$	165,904
		Year Ended December 31, 2013
		Parent			Guarantor			Intercompany			Consolidated
		Issuer			Subsidiaries			Eliminations
		(in thousands)
	Cash flows from operating activities	$	241,911		$	23,354		$	—		$	265,265
	Cash flows from investing activities:
	Additions to oil and gas properties, including acquisitions	(408,441		)	(37,038		)	—			(445,479		)
	Additions to furniture, fixtures and other	(2,254		)	—			—			(2,254		)
	Proceeds from sale of properties and other investing activities	310,704			—			—			310,704
	Cash flows from financing activities:
	Proceeds from debt	420,000			—			—			420,000
	Principal and redemption premium payments on debt	(576,422		)	—			—			(576,422		)
	Intercompany transfers	(13,684		)	13,684			—			—
	Other financing activities	3,336			—			—			3,336
	Change in cash and cash equivalents	(24,850		)	—			—			(24,850		)
	Beginning cash and cash equivalents	79,395			50			—			79,445
	Ending cash and cash equivalents	$	54,545		$	50		$	—		$	54,595
		Year Ended December 31, 2012
		Parent			Guarantor			Intercompany			Consolidated
		Issuer			Subsidiaries			Eliminations
		(in thousands)
	Cash flows from operating activities	$	372,331		$	16,105		$	—		$	388,436
	Cash flows from investing activities:
	Additions to oil and gas properties, including acquisitions	(925,012		)	(33,642		)	—			(958,654		)
	Additions to furniture, fixtures and other	(7,231		)	—			—			(7,231		)
	Proceeds from sale of properties and other investing activities	328,888			—			—			328,888
	Cash flows from financing activities:
	Proceeds from debt	875,826			—			—			875,826
	Principal and redemption premium payments on debt	(595,386		)	—			—			(595,386		)
	Intercompany transfers	(17,537		)	17,537			—			—
	Other financing activities	(9,765		)	—			—			(9,765		)
	Change in cash and cash equivalents	22,114			—			—			22,114
	Beginning cash and cash equivalents	57,281			50			—			57,331
	Ending cash and cash equivalents	$	79,395		$	50		$	—		$	79,445

Summary_of_Significant_Account3

Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summary Of Significant Accounting Policies [Line Items]
Impairment of Oil and Gas Properties	$39,800	$226,600
Anti Dilutive Securities Excluded From Computation of Earnings Per Share Amount	1,406,938		3,162,436
5% Convertible Senior Notes Due 2028 [Member]
Summary Of Significant Accounting Policies [Line Items]
Debt, stated interest rate	5.00%
Debt maturity date	2028
Less Receivable Due to Industry Partner
Summary Of Significant Accounting Policies [Line Items]
Accounts Receivable, Gross	4,700
Receivable from Department of Interior, Gross
Summary Of Significant Accounting Policies [Line Items]
Accounts Receivable, Gross	47,600
West Tavaputs, Unproved [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment of Oil and Gas Properties		2,500
Powder River Oil [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment of Oil and Gas Properties	14,800
Other, Unproved [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment of Oil and Gas Properties		17,100
West Tavaputs, Proved [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment of Oil and Gas Properties	1,000
Paradox Basin, Unproved [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment of Oil and Gas Properties	11,600
Uinta Basin, Unproved [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment of Oil and Gas Properties	6,100
Powder River Oil, Unproved [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment of Oil and Gas Properties	6,400
Proved Oil And Gas Properties [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment of Oil and Gas Properties	15,761	206,953	0
Unproved Oil And Gas Properties [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment of Oil and Gas Properties	$24,082	$19,598	37,348

Summary_of_Significant_Account4

Summary of Significant Accounting Policies - Summary of Accounts Receivable (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for doubtful accounts	($14)	($21)
Total accounts receivable	112,209	97,586
Accrued oil, gas and NGL sales [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable gross	35,099	67,583
Due from joint interest owners [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable gross	27,937	23,507
Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable gross	$49,187	$6,517

Summary_of_Significant_Account5

Summary of Significant Accounting Policies - Net Capitalized Costs and Associated Accumulated Depreciation, Depletion & Amortization and Non Cash Impairments (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounting Policies [Abstract]
Proved properties	$390,482	$485,427
Wells and related equipment and facilities	1,537,370	2,192,754
Support equipment and facilities	68,371	177,224
Materials and supplies	13,069	8,518
Total proved oil and gas properties	2,009,292	2,863,923
Unproved properties	78,898	189,759
Wells and facilities in progress	69,936	56,674
Total unproved oil and gas properties, excluded from amortization	148,834	246,433
Assets held for sale	9,234	0
Accumulated depreciation, depletion, amortization and impairment	-427,954	-926,173
Total oil and gas properties, net	$1,739,406	$2,184,183

Summary_of_Significant_Account6

Summary of Significant Accounting Policies - Non-Cash Impairment Charges, Included within Impairment, Dry Hole Costs and Abandonment Expense in Consolidated Statements of Operations (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Summary Of Significant Accounting Policies [Line Items]
Non-cash impairment of oil and gas properties	$39,800	$226,600
Dry hole costs	101	1,124	21,012
Abandonment expense	6,597	10,723	9,509
Total non-cash impairment, dry hole costs and abandonment expense	46,881	238,398	67,869
Unproved Oil And Gas Properties [Member]
Summary Of Significant Accounting Policies [Line Items]
Non-cash impairment of oil and gas properties	24,082	19,598	37,348
Non Cash Impairment Of Inventory [Member]
Summary Of Significant Accounting Policies [Line Items]
Non-cash impairment of inventory	$340	$0	$0

Summary_of_Significant_Account7

Summary of Significant Accounting Policies - Accounts Payable and Accrued Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounting Policies [Abstract]
Accrued drilling, completion and facility costs	$68,124	$54,750
Accrued lease operating, gathering, transportation and processing expenses	12,526	17,317
Accrued general and administrative expenses	8,482	14,605
Accrued interest payable	14,284	14,860
Accrued payables for property sales	16,296	2,905
Trade payables and other	6,540	11,491
Total accounts payable and accrued liabilities	$126,252	$115,928

Summary_of_Significant_Account8

Summary of Significant Accounting Policies - Calculation of Basic and Diluted Earnings (Loss) Per Share (Detail) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accounting Policies [Abstract]
Net Income (Loss)	$15,081	($192,733)	$582
Basic weighted-average common shares outstanding in period (in shares)	48,010,730	47,496,857	47,194,668
Add dilutive effects of stock options and nonvested equity shares of common stock (in shares)	425,000	0	159,000
Diluted weighted-average common shares outstanding in period (in shares)	48,435,725	47,496,857	47,353,951
Basic net income (loss) per common share (in dollars per share)	$0.31	($4.06)	$0.01
Diluted net income (loss) per common share (in dollars per share)	$0.31	($4.06)	$0.01

Supplemental_Disclosures_of_Ca2

Supplemental Disclosures of Cash Flow Information - Supplemental Cash Flow Information (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Supplemental Cash Flow Information [Abstract]
Cash paid for interest, net of amount capitalized	$65,935	$94,205	$83,718
Cash paid for income taxes	1	1,163	10
Supplemental disclosures of non-cash investing and financing activities:
Accrued receivables - oil and gas properties (1)	42,872	0	0
Accrued liabilities - oil and gas properties	72,297	75,340	49,598
Change in asset retirement obligations, net of disposals	-22,740	-6,996	-25,236
Retirement of treasury stock	2,684	1,778	2,513
Fair value of properties exchanged in non-cash transactions	77,078	0	0
Transfer of lease financing obligation	$36,075	$45,190	$0

Divestitures_and_Assets_Held_f2

Divestitures and Assets Held for Sale - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Proceeds from Divestiture of Businesses			$325,300,000
Accumulated Depreciation Depletion Amortization And Impairment Property Plant And Equipment	454,202,000	949,586,000
Cash proceeds and recognized pre-tax loss			-4,500,000
Gain (Loss) on Disposition of Oil and Gas Property	-100,407,000	0	0
Transfer of lease financing obligation	36,075,000	45,190,000	0
Wind River Basin [Member]
Percentage Of Assets Sold			100.00%
Cash proceeds and recognized pre-tax loss		-3,100,000
Powder River Basin [Member]
Percentage Of Assets Sold			100.00%
Piceance [Member]
Proceeds from Divestiture of Businesses	498,700,000
Gain (Loss) on Disposition of Oil and Gas Property	-79,500,000
Proved properties	1,320,745,000
Furniture, equipment and other	4,907,000
Accumulated depreciation, depletion, amortization and impairment	688,864,000
Total assets	636,788,000
Asset retirement obligation	22,448,000
Transfer of lease financing obligation	36,075,000
Other liabilities	84,000
Total liabilities	58,607,000
Net assets	578,181,000
West Tavaputs [Member]
Proceeds from Divestiture of Businesses	308,700,000
Non-cash impairment of inventory	1,000,000	209,500,000
Powder River Oil [Member]
Proceeds from Divestiture of Businesses	30,000,000
Unproved Oil and Gas Assets Sold	40,600,000
Accumulated Depreciation Depletion Amortization And Impairment Property Plant And Equipment	33,100,000
Net Mineral Acres Sold	17,497
Net Mineral Acres Exchanged Relinquished	29,015
Net Mineral Acres Exchanged Received	7,856
Assets, Fair Value Disclosure, Nonrecurring	71,000,000
Gain (Loss) on Disposition of Oil and Gas Property	-24,500,000
Proved properties	86,200,000
Asset retirement obligation	$1,300,000

Divestitures_and_Assets_Held_f3

Divestitures and Assets Held for Sale - Asset Held for Sale (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Long Lived Assets Held-for-sale [Line Items]
Impairment of Oil and Gas Properties	$39,800	$226,600
Powder River Basin [Member]
Long Lived Assets Held-for-sale [Line Items]
Net Mineral Acres Held For Sale	19,492
Impairment of Oil and Gas Properties	21,100
Powder River Oil, Proved [Member]
Long Lived Assets Held-for-sale [Line Items]
Impairment of Oil and Gas Properties	14,800
Powder River Oil, Unproved [Member]
Long Lived Assets Held-for-sale [Line Items]
Impairment of Oil and Gas Properties	$6,400

LongTerm_Debt_Outstanding_Debt

Long-Term Debt - Outstanding Debt (Detail) (USD $)	12 Months Ended	0 Months Ended
	Dec. 31, 2014	Jul. 23, 2012	Dec. 31, 2013	Jul. 15, 2013	Sep. 27, 2011	Mar. 12, 2012
Debt Instrument [Line Items]
Principal	$803,222,000		$979,082,000
Unamortized Discount	0		0
Carrying Amount	803,222,000		979,082,000
Debt, fair value	725,800,000		847,200,000
Amended Credit Facility [Member]
Debt Instrument [Line Items]
Maturity Date	31-Oct-16
Principal	0		115,000,000
Unamortized Discount	0		0
Carrying Amount	0		115,000,000
Debt, fair value	0		115,000,000
9.875% Senior Notes [Member]
Debt Instrument [Line Items]
Debt, stated interest rate	9.88%			9.88%
Convertible Notes [Member]
Debt Instrument [Line Items]
Maturity Date	15-Mar-28
Principal	25,344,000		25,344,000
Unamortized Discount	0		0
Carrying Amount	25,344,000		25,344,000
Debt, fair value			25,100,000
Aggregate fair value of convertible notes	25,100,000
7.625% Senior Notes [Member]
Debt Instrument [Line Items]
Maturity Date	1-Oct-19
Principal	400,000,000		400,000,000
Unamortized Discount	0		0
Carrying Amount	400,000,000		400,000,000
Debt, stated interest rate	7.63%		7.63%		7.63%
Debt, fair value	359,800,000		430,200,000
7.0% Senior Notes [Member]
Debt Instrument [Line Items]
Maturity Date	15-Oct-22
Principal	400,000,000		400,000,000
Unamortized Discount	0		0
Carrying Amount	400,000,000		400,000,000
Debt, stated interest rate	7.00%		7.00%			7.00%
Debt, fair value	366,000,000		417,000,000
Lease Financing Obligation [Member]
Debt Instrument [Line Items]
Maturity Date	10-Aug-20	10-Aug-20
Principal	3,648,000		43,329,000
Unamortized Discount	0		0
Carrying Amount	3,648,000		43,329,000
Debt, fair value	3,500,000		41,700,000
Total Debt [Member]
Debt Instrument [Line Items]
Principal	828,992,000		983,673,000
Unamortized Discount	0		0
Carrying Amount	828,992,000		983,673,000
Current Portion of Long-Term Debt [Member]
Debt Instrument [Line Items]
Principal	25,770,000		4,591,000
Unamortized Discount	0		0
Carrying Amount	$25,770,000		$4,591,000

LongTerm_Debt_Additional_Infor

Long-Term Debt - Additional Information (Detail) (USD $)	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 20, 2012	Sep. 27, 2011	Jul. 23, 2012	Mar. 12, 2008	Jul. 15, 2013	Mar. 12, 2012
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$375,000,000
Average annual interest rates incurred on Amended Credit Facility	1.90%	2.00%
Line of credit facility, reduced borrowing capacity	349,000,000
Principal amount	803,222,000	979,082,000
(Gain) loss on extinguishment of debt	0	21,460,000	-1,601,000
Purchase of equipment	1,800,000
Minimum [Member]
Debt Instrument [Line Items]
Revolving credit facility, interest rate above London Interbank Offered Rate	1.50%
Revolving credit facility interest rate percent above LIBOR alternate interest rate	0.50%
Commitment fee percentage	0.38%
Maximum [Member]
Debt Instrument [Line Items]
Revolving credit facility, interest rate above London Interbank Offered Rate	2.50%
Revolving credit facility interest rate percent above LIBOR alternate interest rate	1.50%
Commitment fee percentage	0.50%
5% Convertible Senior Notes Due 2028 [Member]
Debt Instrument [Line Items]
Principal amount							172,500,000
Face Amount of Outstanding Convertible Notes Repaid				147,200,000
Percentage of notes put to company				85.00%
Debt, stated interest rate	5.00%
Convertible Notes [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	15-Mar-28
Principal amount		25,300,000
Debt, stated interest rate	5.00%
Debt instrument conversion price rate of redemption	100.00%
Minimum days notice to call Convertible Notes	30 days
Amended Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	31-Oct-16
Line of credit facility, maximum amount outstanding during period	0
Letters of credit issued amount	26,000,000
Principal amount	0	115,000,000
9.875% Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	11.20%							11.20%
Debt, stated interest rate	9.88%							9.88%
7.625% Senior Notes Due 2019 [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date					1-Oct-19
Principal amount					400,000,000
Debt, stated interest rate					7.63%
7.0% Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date	15-Oct-22
Principal amount									400,000,000
Par value of senior notes	103.50%
Lease Financing Obligation [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage						3.30%
Debt instrument, maturity date	10-Aug-20					10-Aug-20
Principal amount	3,648,000	43,329,000
Sale and subsequent lease back						100,800,000
Weighted average implicit rate based on interest expense						3.30%
7.625% Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	8.00%				8.00%
Debt instrument, maturity date	1-Oct-19
Principal amount	400,000,000	400,000,000
Par value of senior notes	103.81%
Debt, stated interest rate	7.63%	7.63%			7.63%
7.0% Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	7.20%								7.20%
Debt instrument, maturity date	15-Oct-22
Principal amount	$400,000,000	$400,000,000
Debt, stated interest rate	7.00%	7.00%							7.00%

LongTerm_Debt_Cash_and_NonCash

Long-Term Debt - Cash and Non-Cash Portion of Interest Expense Related to Long Term Debt (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jul. 15, 2013	Mar. 31, 2012	Sep. 27, 2011	Mar. 12, 2012	Jul. 23, 2012
Debt Instrument [Line Items]
Principal	$803,222,000	$979,082,000
Cash interest [Member]
Debt Instrument [Line Items]
Amended Credit Facility interest	4,837,000	6,802,000	5,652,000
Non-cash interest [Member]
Debt Instrument [Line Items]
Amended Credit Facility interest	2,342,000	2,342,000	2,342,000
9.875% Senior Notes [Member]
Debt Instrument [Line Items]
Debt, stated interest rate	9.88%			9.88%
Effective interest rate of debt instrument	11.20%			11.20%
9.875% Senior Notes [Member] | Cash interest [Member]
Debt Instrument [Line Items]
Senior Notes interest	0	13,373,000	24,688,000
9.875% Senior Notes [Member] | Non-cash interest [Member]
Debt Instrument [Line Items]
Senior Notes interest	0	1,361,000	2,571,000
5% Convertible Notes [Member]
Debt Instrument [Line Items]
Debt, stated interest rate	5.00%
Principal					25,300,000
Convertible Notes [Member]
Debt Instrument [Line Items]
Principal	25,344,000	25,344,000
Convertible Notes [Member] | Cash interest [Member]
Debt Instrument [Line Items]
Convertible Notes interest	1,264,000	1,267,000	2,909,000
Convertible Notes [Member] | Non-cash interest [Member]
Debt Instrument [Line Items]
Convertible Notes interest	5,000	6,000	1,771,000
7.625% Senior Notes [Member]
Debt Instrument [Line Items]
Debt, stated interest rate	7.63%	7.63%				7.63%
Effective interest rate of debt instrument	8.00%					8.00%
Principal	400,000,000	400,000,000
7.625% Senior Notes [Member] | Cash interest [Member]
Debt Instrument [Line Items]
Senior Notes interest	30,500,000	30,500,000	30,500,000
7.625% Senior Notes [Member] | Non-cash interest [Member]
Debt Instrument [Line Items]
Senior Notes interest	1,090,000	1,070,000	1,066,000
7.0% Senior Notes Due 2022 [Member]
Debt Instrument [Line Items]
Principal							400,000,000
7.0% Senior Notes [Member]
Debt Instrument [Line Items]
Debt, stated interest rate	7.00%	7.00%					7.00%
Effective interest rate of debt instrument	7.20%						7.20%
Principal	400,000,000	400,000,000
7.0% Senior Notes [Member] | Cash interest [Member]
Debt Instrument [Line Items]
Senior Notes interest	28,000,000	28,000,000	22,400,000
7.0% Senior Notes [Member] | Non-cash interest [Member]
Debt Instrument [Line Items]
Senior Notes interest	814,000	795,000	659,000
Lease Financing Obligation [Member]
Debt Instrument [Line Items]
Effective interest rate of debt instrument								3.30%
Principal	3,648,000	43,329,000
Lease Financing Obligation [Member] | Cash interest [Member]
Debt Instrument [Line Items]
Financial Obligation interest	638,000	2,852,000	1,353,000
Lease Financing Obligation [Member] | Non-cash interest [Member]
Debt Instrument [Line Items]
Financial Obligation interest	$12,000	$30,000	$15,000

Asset_Retirement_Obligations_S

Asset Retirement Obligations - Schedule of Asset Retirement Obligations (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Asset Retirement Obligation Disclosure [Abstract]
Liabilities of Assets Held-for-sale	$146	$0	$0
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning of period	43,005	47,616	69,302
Liabilities incurred	4,027	2,359	4,046
Liabilities settled	-6,283	-1,096	-871
Disposition of properties	-23,722	-13,543	-33,560
Accretion expense	2,587	3,481	4,421
Revisions to estimate	3,238	4,188	4,278
End of period	22,852	43,005	47,616
Less: Current asset retirement obligations	1,114	3,805	1,566
Long-term asset retirement obligations	$21,592	$39,200	$46,050

Fair_Value_Measurements_Balanc

Fair Value Measurements - Balance Sheet Grouping (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Assets
Deferred Compensation Plan	$1,069	$941
Cash Equivalents - Money Market Funds	165,904	54,595	79,445	57,331
Cash Equivalents - Money Market Funds [Member]
Assets
Cash Equivalents - Money Market Funds	75,066	53
Commodity Derivatives [Member]
Assets
Commodity Derivatives	195,176	11,483
Liabilities
Commodity Derivatives	200	14,771
Level 1 [Member]
Assets
Deferred Compensation Plan	1,069	941
Level 1 [Member] | Cash Equivalents - Money Market Funds [Member]
Assets
Cash Equivalents - Money Market Funds	75,066	53
Level 1 [Member] | Commodity Derivatives [Member]
Assets
Commodity Derivatives	0	0
Liabilities
Commodity Derivatives	0	0
Level 2 [Member]
Assets
Deferred Compensation Plan	0	0
Level 2 [Member] | Cash Equivalents - Money Market Funds [Member]
Assets
Cash Equivalents - Money Market Funds	0	0
Level 2 [Member] | Commodity Derivatives [Member]
Assets
Commodity Derivatives	195,176	11,483
Liabilities
Commodity Derivatives	200	14,771
Level 3 [Member]
Assets
Deferred Compensation Plan	0	0
Level 3 [Member] | Cash Equivalents - Money Market Funds [Member]
Assets
Cash Equivalents - Money Market Funds	0	0
Level 3 [Member] | Commodity Derivatives [Member]
Assets
Commodity Derivatives	0	0
Liabilities
Commodity Derivatives	$0	$0

Fair_Value_Measurements_Additi

Fair Value Measurements - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Jul. 15, 2013	Sep. 27, 2011	Mar. 12, 2012
Fair Value Measurements [Line Items]
Net Carrying Value, Proved Property	$6,700,000
Net Carrying Value, Unproved Property	2,500,000
Debt, fair value	725,800,000	847,200,000
Non-cash impairment of oil and gas properties	39,800,000	226,600,000
9.875% Senior Notes [Member]
Fair Value Measurements [Line Items]
Debt, stated interest rate	9.88%		9.88%
7.625% Senior Notes [Member]
Fair Value Measurements [Line Items]
Debt, stated interest rate	7.63%	7.63%		7.63%
Debt, fair value	359,800,000	430,200,000
7.0% Senior Notes [Member]
Fair Value Measurements [Line Items]
Debt, stated interest rate	7.00%	7.00%			7.00%
Debt, fair value	366,000,000	417,000,000
Amended Credit Facility [Member]
Fair Value Measurements [Line Items]
Debt, fair value	0	115,000,000
Convertible Notes [Member]
Fair Value Measurements [Line Items]
Debt, fair value		25,100,000
Lease Financing Obligation [Member]
Fair Value Measurements [Line Items]
Debt, fair value	3,500,000	41,700,000
Powder River Basin [Member]
Fair Value Measurements [Line Items]
Non-cash impairment of oil and gas properties	21,100,000
West Tavaputs [Member]
Fair Value Measurements [Line Items]
Non-cash impairment of oil and gas properties		$209,500,000

Fair_Value_Measurements_Assets

Fair Value Measurements Assets and Liabilities Measured on a Non-recurring Basis (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Impairment of Oil and Gas Properties	$39,800	$226,600
Fair Value, Measurements, Nonrecurring [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Proved property impairments	0	0
Unproved property impairments	0	0
Fair Value, Measurements, Nonrecurring [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Proved property impairments	0	0
Unproved property impairments	0	0
Fair Value, Measurements, Nonrecurring [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Proved property impairments	15,761	206,953
Unproved property impairments	24,082	19,598
Estimate of Fair Value [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Proved property impairments	1,588,038	1,937,913
Unproved property impairments	$151,368	$246,270

Derivative_Instruments_Fair_Va

Derivative Instruments - Fair Value Amounts of Derivative Instruments (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets	$195,176,000	$11,483,000
Gross Amounts Offset in the Balance Sheet	-200,000	-8,771,000
Net Amounts of Assets Presented in the Balance Sheet	194,976,000	2,712,000
Gross Amounts of Recognized Liabilities	-200,000	-14,771,000
Gross Amounts Offset in the Balance Sheet	200,000	8,771,000
Net Amounts of Liabilities Presented in the Balance Sheet	0	-6,000,000
Derivative Financial Instruments, Liabilities [Member]
Derivatives, Fair Value [Line Items]
Balance included in other noncurrent liabilities excluding hedge instruments	3,000,000	3,500,000
Derivative Assets [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets	145,426,000	8,259,000
Gross Amounts Offset in the Balance Sheet	-200,000	-8,086,000
Net Amounts of Assets Presented in the Balance Sheet	145,226,000	173,000
Deferred Financing Costs, Derivative Assets and Other Non Current Assets [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Assets	49,750,000	3,224,000
Gross Amounts Offset in the Balance Sheet	0	-685,000
Net Amounts of Assets Presented in the Balance Sheet	49,750,000	2,539,000
Derivative Liabilities [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Liabilities	-200,000	-14,074,000
Gross Amounts Offset in the Balance Sheet	200,000	8,086,000
Net Amounts of Liabilities Presented in the Balance Sheet	0	-5,988,000
Derivative and Other Non Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Gross Amounts of Recognized Liabilities	0	-697,000
Gross Amounts Offset in the Balance Sheet	0	685,000
Net Amounts of Liabilities Presented in the Balance Sheet	$0	($12,000)

Derivative_Instruments_Cash_Fl

Derivative Instruments - Cash Flow Hedge Gain and Losses (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Recognized in AOCI	$0	$0	$0
Amount of Gain (Loss) Reclassified from AOCI into Income (net of tax)	0	0	0
Derivatives Qualifying as Cash Flow Hedges	Commodity Hedges	Commodity Hedges	Commodity Hedges
Effect of derivative financial instruments, taxes	410	2,802	30,458
Commodity Derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain (Loss) Reclassified from AOCI into Income (net of tax)	$669	$4,663	$50,712

Derivative_Instruments_Financi

Derivative Instruments - Financial Instruments for Hedging Volume (Detail)	Dec. 31, 2014
	MMBTU
	bbl
2015 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Oil (Bbls)	4,022,600
Natural Gas (MMbtu)	7,207,000
2016 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Oil (Bbls)	1,737,000
Natural Gas (MMbtu)	1,830,000
2017 [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Oil (Bbls)	365,000
Natural Gas (MMbtu)	0

Derivative_Instruments_Realize

Derivative Instruments - Realized and Unrealized Gains and Losses on Commodity Derivative Instruments (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Operating and other revenues	$472,291	$568,093	$700,195
Oil and Natural Gas Derivative Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Operating and other revenues	1,070	7,463	81,166
Total commodity derivative gain (loss)	$197,447	($23,068)	$72,759

Derivative_Instruments_Additio

Derivative Instruments - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014
	Counterparty
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Number of counterparties for hedges at period end	8

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Net	($177.80)	($161.50)
U.S. federal income tax rate	35.00%
Federal tax net operating loss carryforwards	168.2
Federal AMT credit carryforward	1.7
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforward, Amount	$7.90

Income_Taxes_Expense_for_Incom

Income Taxes - Expense for Income Taxes (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Current Federal	$1,220	($1,233)	$966
Current State	44	-352	886
Current Foreign	1	2	1
Deferred Federal	10,246	-107,300	100
Deferred State	6,398	-9,750	-317
Income tax expense (benefit)	$17,909	($118,633)	$1,636

Income_Taxes_Reconciliation_of

Income Taxes - Reconciliation of Actual Income Tax Expense (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Income tax expense at the federal statutory rate	$11,546	($108,978)	$777
State income taxes, net of federal tax effect	932	-6,702	-269
Incentive stock compensation	199	678	635
Nondeductible political contributions and lobbying costs	108	96	271
Nondeductible officer compensation	229	138	0
Other permanent items	89	52	26
Deferred tax related to the changes in overall state tax rates	5,230	-3,851	310
Other, net	-424	-66	-114
Income tax expense (benefit)	$17,909	($118,633)	$1,636

Income_Taxes_Components_of_Def

Income Taxes - Components of Deferred Tax Assets and Deferred Tax Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Components of Deferred Tax Assets and Liabilities [Abstract]
Derivative instruments	($54,933)	($89)
Accrued expenses	229	400
Bad debt expense	5	8
Prepaid expenses	-702	-648
Other	-17	130
Total current deferred tax assets (liabilities)	-55,418	-199
Net operating loss carryforward	56,529	75,511
Deferred offering costs	1,182	1,243
Stock-based compensation	15,767	14,200
Deferred rent	787	962
Long-term derivative instruments	-18,818	1,306
Minimum tax credit carryforward	1,690	688
Deferred compensation	1,062	999
State tax credit carryforwards	5,110	5,871
Production payment loan	0	3,839
Financing obligation	1,586	16,227
Other	250	222
Less: Valuation allowance	-5,110	-5,871
Total long-term deferred tax assets	78,853	113,891
Oil and gas properties	-182,385	-276,523
Total long-term deferred tax liabilities	-201,203	-275,217
Net long-term deferred tax liabilities	($122,350)	($161,326)

Stockholders_Equity_Additional

Stockholders' Equity - Additional Information (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Oct. 31, 2004
Class of Stock [Line Items]
Preferred stock, shares authorized	75,000,000
Preferred stock, par value	$0.00
Common stock, shares authorized	150,000,000	150,000,000
Common stock, par value	$0.00	$0.00
Series A Junior Participating Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, par value			$0.00
Preferred stock designated as Junior Participating Preferred Stock			150,000
Preferred stock, shares outstanding	0
Preferred stock, voting rights	1,000

Stockholders_Equity_Schedule_o

Stockholders' Equity - Schedule of Stockholders Equity (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares at beginning of period	49,152,448	48,150,475	47,809,903
Exercise of common stock options	7,926	259,699	36,560
Shares issued for 401(k) plan	36,533	47,235	41,415
Shares issued for directors' fees	44,551	52,081	12,973
Shares issued for nonvested equity shares of common stock	857,870	1,081,259	454,666
Shares retired or forfeited	-572,691	-438,301	-205,042
Shares at end of period	49,526,637	49,152,448	48,150,475
Shares at beginning of period	0	0	0
Treasury stock acquired	116,813	96,880	92,393
Treasury stock retired	-116,813	-96,880	-92,393
Shares at end of period	0	0	0

Stockholders_Equity_Schedule_o1

Stockholders Equity - Schedule of Accumulated Other Comprehensive Income (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss), before Tax [Roll Forward]
Accumulated other comprehensive income, Gross Beginning	$1,079	$8,544	$89,714
Reclassification adjustment for realized gains on hedges included in net income, Gross	-1,079	-7,465	-81,170
Accumulated other comprehensive income, Gross Ending	0	1,079	8,544
Accumulated Other Comprehensive Income (Loss), Tax [Roll Forward]
Accumulated other comprehensive income, Tax Effect Beginning	-410	-3,212	-33,670
Reclassification adjustment for realized gains on hedges included in net income, Tax Effect	410	2,802	30,458
Accumulated other comprehensive income, Tax Effect Ending	0	-410	-3,212
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive income, Net of Tax Beginning	-669	-5,332	-56,044
Reclassification adjustment for realized gains on hedges included in net income, Net of Tax	-669	-4,663	-50,712
Accumulated other comprehensive income, Net of Tax Ending	$0	$669	$5,332

Equity_Incentive_Compensation_2

Equity Incentive Compensation Plans and Other Employee Benefits - Additional Information (Detail) (USD $)	12 Months Ended			1 Months Ended			12 Months Ended	1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	31-May-12	Feb. 28, 2014	Mar. 31, 2012	Dec. 31, 2011	Feb. 28, 2013
	age
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$15,700,000
Weighted-average period (years)	2 years 3 months 18 days
Expected dividend yield	0.00%		0.00%
Weighted average expected term (in years)			4 years 3 months 18 days
Weighted average expected terms range, minimum period	4 years 3 months 18 days
Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Weighted Average Expected Term Maximum	4 years 7 months 6 days
Percentage of grant's vesting on anniversary date	25.00%
Annual compounded forfeiture rate, minimum	4.00%
Annual compounded forfeiture rate, maximum	10.00%
Fair value of performance-based shares vested in year	800,000		2,600,000
Options to purchase shares of common stock, Weighted Average Price Per Share			$11.02
Total intrinsic value of options exercised	100,000	500,000	400,000
Proceeds from stock option exercises	126,000	6,385,000	673,000
Fair value of equity awards	8,000,000	8,100,000	8,600,000
Non-cash stock based compensation	10,973,000	15,634,000	16,370,000
Performance shares set as side at the end of plan			179,987
Minimum age for employees to be eligible under employee directed savings plan	21
Percentage of employee's contribution matched by the company	100.00%
Percentage of employee's pretax income	6.00%
Percentage of common stock matched by company	50.00%
Cash and common stock contributions	1,700,000	1,900,000	2,000,000
Percentage of employee's cash compensation reached under cash matching contributions	6.00%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average expected term (in years)	1 month 2 days
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average expected term (in years)	6 years
2012 Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares granted				2,051,402
Aggregate number of shares of common stock subject to options or stock appreciation granted				500,000
Expiration period of option granted				10 years
Two Thousand And Fourteen Performance Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted percentage of stockholders return related to performance goals					60.00%
Performance goals percentage for change in discretionary cash flows					40.00%
Two Thousand And Fourteen Performance Program [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of total grant that will vest for metrics met at stretch level					200.00%	200.00%
Percentage of total grant that will vest for metrics met at target level					100.00%
Percentage of performance-based awards allowed to vest within a year					25.00%
2010 Performance Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percent of Performance Based Shares Vested	19.80%	0.00%	26.60%				25.90%
Total Percent of Performance Based Shares Vested	72.30%
Number of Performance Based Shares Vested	21,968	0	57,944				59,582
Percent of Market Based Shares Vested	33.40%	0.00%	12.50%				37.50%
Total Percent of Market Based Shares Vested	83.40%
Number of Market Based Shares Vested	9,242	0	6,801				21,574
2012 Performance Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted percentage of stockholders return related to performance goals						33.30%
Performance goals percentage for change in discretionary cash flows						33.30%
Performance goals percentage weight for change in proved properties						33.30%
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	0
2012 Performance Program [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of total grant that will vest for metrics met at stretch level						200.00%
Percentage of performance-based awards allowed to vest within a year						50.00%
Percentage of total grant that will vest for metrics met at target level						100.00%
2013 Performance Program [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of total grant that will vest for metrics met at stretch level								200.00%
Weighted percentage of stockholders return related to performance goals								33.30%
Performance goals percentage for change in discretionary cash flows								33.30%
Performance goals percentage weight for change in proved properties								33.30%
Percentage of performance-based awards allowed to vest within a year								50.00%
Percentage of total grant that will vest for metrics met at target level								100.00%
Performance shares set as side at the end of plan		450,544
Percentage of performance-based awards allowed to vest within a year								25.00%
Maximum number of common stock vest as percentage of performance shares granted								200.00%
2013 Performance Program [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of total grant that will vest for metrics met at stretch level								200.00%
Percentage of total grant that will vest for metrics met at target level								100.00%
Nonvested Performance Based Equity Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	315,661	450,544	179,987
Non-cash stock based compensation	$990,000	$2,174,000	$1,079,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	42,833	0	64,745

Equity_Incentive_Compensation_3

Equity Incentive Compensation Plans and Other Employee Benefits - Non-Cash Stock-Based Compensation Cost Related to Equity Awards (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock Based Compensation [Line Items]
Non-cash stock based compensation	$10,973,000	$15,634,000	$16,370,000
Common Stock Options [Member]
Stock Based Compensation [Line Items]
Non-cash stock based compensation	2,073,000	4,696,000	7,189,000
Nonvested Equity Common Stock [Member]
Stock Based Compensation [Line Items]
Non-cash stock based compensation	6,845,000	7,492,000	7,394,000
Nonvested Equity Common Stock Units [Member]
Stock Based Compensation [Line Items]
Non-cash stock based compensation	1,065,000	1,272,000	708,000
Nonvested Performance-Based Equity [Member]
Stock Based Compensation [Line Items]
Non-cash stock based compensation	990,000	2,174,000	1,079,000
Performance Based Awards [Member]
Stock Based Compensation [Line Items]
Share based compensation cost related to prior performance goal	$100,000	$400,000	$200,000

Equity_Incentive_Compensation_4

Equity Incentive Compensation Plans and Other Employee Benefits - Fair Value Assumptions and Methodology (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2012
Disclosure Equity Incentive Compensation Plans And Other Employee Benefits Fair Value Assumptions And Methodology [Abstract]
Weighted average volatility		51.00%
Expected dividend yield	0.00%	0.00%
Weighted average expected term (in years)		4 years 3 months 18 days
Weighted average risk-free rate		1.80%

Equity_Incentive_Compensation_5

Equity Incentive Compensation Plans and Other Employee Benefits - Summary of Share-Based Option Activity (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at January 1, 2014	1,748,696
Granted	0
Exercised	-7,926	-259,699	-36,560
Forfeited or expired	-401,405
Outstanding at December 31, 2014	1,339,365	1,748,696
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Outstanding at January 1, 2014	$32.66
Granted	$0
Exercised	$18.22
Forfeited or expired	$33.56
Outstanding at December 31, 2014	$32.47	$32.66
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Outstanding at December 31, 2014, Weighted-average remaining contractual term	1 year 4 months 13 days
Outstanding at December 31, 2014, Aggregate intrinsic value	$0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest [Abstract]
Vested and expected to vest, at December 31, 2014 through the life of the options	1,332,062
Vested and exercisable at December 31, 2014	1,151,004
Vested, or expected to vest, at December 31, 2014 through the life of the options, Weighted-average Exercise Price	$30.33
Vested and exercisable at December 31, 2014, Weighted-average Exercise Price	$33.05
Vested, or expected to vest, at December 31, 2014 through the life of the options, Weighted-average remaining contractual term	1 year 11 months 1 day
Vested and exercisable at December 31, 2014, Weighted-average remaining contractual term	1 year 7 months 6 days
Vested and expected to vest, at December 31, 2014 through the life of the options, Aggregate intrinsic value	0
Vested and exercisable at December 31, 2014, Aggregate intrinsic value	$0

Equity_Incentive_Compensation_6

Equity Incentive Compensation Plans and Other Employee Benefits - Summary of Nonvested Equity Shares of Common Stock (Detail) (Nonvested Equity Common Stock [Member], USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Nonvested Equity Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding Beginning, Shares	756,118	579,188	639,628
Granted, Shares	542,209	630,715	274,679
Vested, Shares	-292,168	-270,482	-241,736
Forfeited or expired, Shares	-213,095	-183,303	-93,383
Outstanding Ending, Shares	793,064	756,118	579,188
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Outstanding Beginning, Weighted-average Grant Date Fair-Value	$22.17	$31.02	$35.12
Granted, Weighted-average Grant Date Fair-Value	$22	$17.98	$25.62
Vested, Weighted-average Grant Date Fair-Value	$24.05	$29.82	$34.61
Forfeited or expired, Weighted-average Grant Date Fair-Value	$21.99	$24.87	$33.39
Outstanding Ending, Weighted-average Grant Date Fair-Value	$21.47	$22.17	$31.02

Equity_Incentive_Compensation_7

Equity Incentive Compensation Plans and Other Employee Benefits - Summary of Nonvested Equity Shares of Common Stock Issued for Payment of Director Fees (Detail) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding Beginning, Shares	55,778	49,185	0
Granted, Shares	45,928	56,464	58,983
Vested, Shares	-46,761	-49,871	-9,798
Forfeited or expired, Shares	0	0	0
Outstanding Ending, Shares	54,945	55,778	49,185
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Outstanding Beginning, Weighted-average Grant Date Fair-Value	$19.35	$18.50	$0
Granted, Weighted-average Grant Date Fair-Value	$24.49	$22.33	$18.83
Vested, Weighted-average Grant Date Fair-Value	$22.25	$18.96	$20.51
Forfeited or expired, Weighted-average Grant Date Fair-Value	$0	$0	$0
Outstanding Ending, Weighted-average Grant Date Fair-Value	$23.84	$19.35	$18.50
Performance Based Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Compensation Cost Related To Prior Performance Goal	$0.10	$0.40	$0.20

Equity_Incentive_Compensation_8

Equity Incentive Compensation Plans and Other Employee Benefits - Summary of Nonvested Performance-Based Equity Shares of Common Stock (Detail) (Nonvested Performance-Based Equity [Member], USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Nonvested Performance-Based Equity [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding Beginning, Shares	584,032	291,606	195,630
Vested, Shares	-42,833	0	-64,745
Modified, performance goals revised, Shares	0	-108,933	-121,191
Modified, performance goals revised, Shares	0	108,933	121,191
Granted, Shares	315,661	450,544	179,987
Forfeited or expired, Shares	-242,783	-158,118	-19,266
Outstanding Ending, Shares	614,077	584,032	291,606
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Outstanding Beginning, Weighted-average Grant Date Fair-Value	$19.80	$26.85	$33.36
Vested, Weighted-average Grant Date Fair-Value	$19.51	$0	$39.90
Modified, performance goals revised, Weighted-average Grant Date Fair Value	$0	$27.75	$39.90
Modified, performance goals revised, Weighted-average Grant Date Fair Value	$0	$18.18	$27.75
Granted, Weighted-average Grant Date Fair-Value	$23.86	$19.99	$27.57
Forfeited or expired, Weighted-average Grant Date Fair-Value	$22.13	$22.52	$33.82
Outstanding Ending, Weighted-average Grant Date Fair-Value	$19.62	$19.80	$26.85

Equity_Incentive_Compensation_9

Equity Incentive Compensation Plans and Other Employee Benefits - Director Fees (Detail) (Director [Member], USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Director fees (shares)	3,928	16,151	12,973
Stock-based compensation (in thousands)	$75	$351	$276

Recovered_Sheet1

Equity Incentive Compensation Plans and Other Employee Benefits - Deferred Compensation Liability (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Deferred Compensation Liability [Roll Forward]
Beginning deferred compensation liability balance	$941	$966
Employee contributions	441	206
Company matching contributions	160	115
Distributions	-503	-441
Participant earnings (losses)	30	95
Ending deferred compensation liability balance	1,069	941
Deferred Compensation Liability [Abstract]
Amount to be paid within one year	220	451
Remaining balance to be paid beyond one year	$849	$490

Recovered_Sheet2

Equity Incentive Compensation Plans and Other Employee Benefits - Deferred Compensation Investment Assets (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Compensation Liability [Roll Forward]
Beginning investment balance	$941	$966
Investment purchases	601	321
Distributions	-503	-441
Earnings (losses)	30	95
Ending investment balance	$1,069	$941

Significant_Customers_and_Othe1

Significant Customers and Other Concentrations - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
	Customer	Customer	Customer
Concentration Risk [Line Items]
Number of counterparties of which hedges are in place	8
Sales Revenue, Product Line [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Customers account for production revenues	2	1	2

Commitments_and_Contingencies_1

Commitments and Contingencies - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Contingencies And Commitments [Line Items]
Number of Firm Transportation Contracts	2
Total financial commitment on take-or-pay purchase agreements for supply of carbon dioxide	$1.70
Minimum [Member]
Contingencies And Commitments [Line Items]
Contract term, years	6 years
Commitment Ending November 30, 2015 [Member]
Contingencies And Commitments [Line Items]
Volume Commitment Satisfied	19,300,000
Minimum Volume Commitment	450,000,000
Minimum Volume Commitment Deficiency Payment	0.8
Minimum Volume Commitment, Estimated Deficiency Payment	$0.70

Commitments_and_Contingencies_2

Commitments and Contingencies - Schedule of Aggregate Undiscounted Minimum Future Lease Payments (Detail) (Lease Financing Obligation [Member], USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Lease Financing Obligation [Member]
Future Minimum Lease Payments Under Capital Leases And Operating Leases For Continuing Operations [Line Items]
2015	$537
2016	537
2017	537
2018	537
2019	1,826
Thereafter	0
Total	$3,974

Commitments_and_Contingencies_3

Commitments and Contingencies - Gross Future Minimum Transportation Demand and Firm Processing Charges (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Commitments and Contingencies Disclosure [Abstract]
2015	$17,742
2016	18,692
2017	18,692
2018	18,692
2019	18,692
Thereafter	29,595
Total	$122,105

Commitments_and_Contingencies_4

Commitments and Contingencies - Future Minimum Annual Payments under Drilling, Lease and Other Agreements (Detail) (Office & Equipment Leases, USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Office & Equipment Leases
Operating Leased Assets [Line Items]
2015	$4,204
2016	2,838
2017	2,690
2018	2,525
2019	634
Thereafter	0
Total	$12,891

Guarantor_Subsidiaries_Additio

Guarantor Subsidiaries - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Sep. 27, 2011	Mar. 12, 2012
Guarantor Subsidiaries [Line Items]
Percentage of Guarantor Subsidiaries	100.00%
7.625% Senior Notes [Member]
Guarantor Subsidiaries [Line Items]
Debt, stated interest rate	7.63%	7.63%	7.63%
7.0% Senior Notes [Member]
Guarantor Subsidiaries [Line Items]
Debt, stated interest rate	7.00%	7.00%		7.00%

Guarantor_Subsidiaries_Schedul

Guarantor Subsidiaries - Schedule of Condensed Consolidating Balance Sheets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
In Thousands, unless otherwise specified
Assets:
Current assets	$426,105	$157,247
Property and equipment, net	1,753,121	2,202,496
Intercompany receivable (payable)	0	0
Investment in subsidiaries	0	0
Noncurrent assets	65,258	21,770
Total	2,244,484	2,381,513
Liabilities and Stockholders’ Equity:
Current liabilities	264,687	192,719
Long-term debt	803,222	979,082
Deferred income taxes	122,350	161,326
Other noncurrent liabilities	24,737	42,668
Stockholders’ equity	1,029,488	1,005,718	1,182,775	1,218,838
Total	2,244,484	2,381,513
Parent Issuer [Member]
Assets:
Current assets	426,103	154,986
Property and equipment, net	1,672,513	2,127,624
Intercompany receivable (payable)	59,592	59,076
Investment in subsidiaries	18,647	12,063
Noncurrent assets	65,258	21,770
Total	2,242,113	2,375,519
Liabilities and Stockholders’ Equity:
Current liabilities	263,649	192,106
Long-term debt	803,222	979,082
Deferred income taxes	122,350	158,071
Other noncurrent liabilities	23,404	40,542
Stockholders’ equity	1,029,488	1,005,718
Total	2,242,113	2,375,519
Guarantor Subsidiaries [Member]
Assets:
Current assets	2	2,261
Property and equipment, net	80,608	74,872
Intercompany receivable (payable)	-59,592	-59,076
Investment in subsidiaries	0	0
Noncurrent assets	0	0
Total	21,018	18,057
Liabilities and Stockholders’ Equity:
Current liabilities	1,038	613
Long-term debt	0	0
Deferred income taxes	0	3,255
Other noncurrent liabilities	1,333	2,126
Stockholders’ equity	18,647	12,063
Total	21,018	18,057
Intercompany Eliminations [Member]
Assets:
Current assets	0	0
Property and equipment, net	0	0
Intercompany receivable (payable)	0	0
Investment in subsidiaries	-18,647	-12,063
Noncurrent assets	0	0
Total	-18,647	-12,063
Liabilities and Stockholders’ Equity:
Current liabilities	0	0
Long-term debt	0	0
Deferred income taxes	0	0
Other noncurrent liabilities	0	0
Stockholders’ equity	-18,647	-12,063
Total	($18,647)	($12,063)

Guarantor_Subsidiaries_Schedul1

Guarantor Subsidiaries - Schedule of Condensed Consolidating Statements of Operations (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Operating and other revenues	$472,291	$568,093	$700,195
Operating expenses	-515,058	-683,168	-608,320
General and administrative	-53,361	-64,902	-68,666
Interest income and other income (expense)	129,118	-131,389	-20,991
Income (loss) before income taxes and equity in earnings (loss) of subsidiaries	32,990	-311,366	2,218
Provision for income taxes	-17,909	118,633	-1,636
Equity in earnings (loss) of subsidiaries	0	0	0
Net income (loss)	15,081	-192,733	582
Parent Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Operating and other revenues	447,907	538,932	683,319
Operating expenses	-497,258	-655,219	-599,215
General and administrative	-53,361	-64,902	-68,666
Interest income and other income (expense)	129,118	-131,389	-20,991
Income (loss) before income taxes and equity in earnings (loss) of subsidiaries	26,406	-312,578	-5,553
Provision for income taxes	-17,909	118,633	-1,636
Equity in earnings (loss) of subsidiaries	6,584	1,212	7,771
Net income (loss)	15,081	-192,733	582
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Operating and other revenues	24,384	29,161	16,876
Operating expenses	-17,800	-27,949	-9,105
General and administrative	0	0	0
Interest income and other income (expense)	0	0	0
Income (loss) before income taxes and equity in earnings (loss) of subsidiaries	6,584	1,212	7,771
Provision for income taxes	0	0	0
Equity in earnings (loss) of subsidiaries	0	0	0
Net income (loss)	6,584	1,212	7,771
Intercompany Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Operating and other revenues	0	0	0
Operating expenses	0	0	0
General and administrative	0	0	0
Interest income and other income (expense)	0	0	0
Income (loss) before income taxes and equity in earnings (loss) of subsidiaries	0	0	0
Provision for income taxes	0	0	0
Equity in earnings (loss) of subsidiaries	-6,584	-1,212	-7,771
Net income (loss)	($6,584)	($1,212)	($7,771)

Guarantor_Subsidiaries_Schedul2

Guarantor Subsidiaries - Schedule of Condensed Consolidating Statements of Comprehensive Income (Loss) (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Net Income (Loss)	$15,081	($192,733)	$582
Effect of derivative financial instruments	-669	-4,663	-50,712
Other comprehensive loss	-669	-4,663	-50,712
Comprehensive Income (Loss)	14,412	-197,396	-50,130
Parent Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Net Income (Loss)	15,081	-192,733	582
Effect of derivative financial instruments	-669	-4,663	-50,712
Other comprehensive loss	-669	-4,663	-50,712
Comprehensive Income (Loss)	14,412	-197,396	-50,130
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net Income (Loss)	6,584	1,212	7,771
Effect of derivative financial instruments	0	0	0
Other comprehensive loss	0	0	0
Comprehensive Income (Loss)	6,584	1,212	7,771
Intercompany Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net Income (Loss)	-6,584	-1,212	-7,771
Effect of derivative financial instruments	0	0	0
Other comprehensive loss	0	0	0
Comprehensive Income (Loss)	($6,584)	($1,212)	($7,771)

Guarantor_Subsidiaries_Schedul3

Guarantor Subsidiaries - Schedule of Condensed Consolidating Statements of Cash Flows (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Condensed Financial Statements, Captions [Line Items]
Cash flows from operating activities	$261,717	$265,265	$388,436
Cash flows from investing activities:
Additions to oil and gas properties, including acquisitions	-580,943	-445,479	-958,654
Additions to furniture, fixtures and other	-3,658	-2,254	-7,231
Proceeds from sale of properties and other investing activities	555,296	310,704	328,888
Intercompany Transfers Investing Activities	0
Cash flows from financing activities:
Proceeds from debt	165,000	420,000	875,826
Principal and redemption premium payments on debt	-283,546	-576,422	-595,386
Intercompany transfers	0	0	0
Other financing activities	-2,557	3,336	-9,765
Increase (Decrease) in Cash and Cash Equivalents	111,309	-24,850	22,114
Beginning Cash and Cash Equivalents	54,595	79,445	57,331
Ending Cash and Cash Equivalents	165,904	54,595	79,445
Parent Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Cash flows from operating activities	241,628	241,911	372,331
Cash flows from investing activities:
Additions to oil and gas properties, including acquisitions	-562,141	-408,441	-925,012
Additions to furniture, fixtures and other	-3,658	-2,254	-7,231
Proceeds from sale of properties and other investing activities	553,477	310,704	328,888
Intercompany Transfers Investing Activities	3,156
Cash flows from financing activities:
Proceeds from debt	165,000	420,000	875,826
Principal and redemption premium payments on debt	-283,546	-576,422	-595,386
Intercompany transfers	0	-13,684	-17,537
Other financing activities	-2,557	3,336	-9,765
Increase (Decrease) in Cash and Cash Equivalents	111,359	-24,850	22,114
Beginning Cash and Cash Equivalents	54,545	79,395	57,281
Ending Cash and Cash Equivalents	165,904	54,545	79,395
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Cash flows from operating activities	20,089	23,354	16,105
Cash flows from investing activities:
Additions to oil and gas properties, including acquisitions	-18,802	-37,038	-33,642
Additions to furniture, fixtures and other	0	0	0
Proceeds from sale of properties and other investing activities	1,819	0	0
Intercompany Transfers Investing Activities	0
Cash flows from financing activities:
Proceeds from debt	0	0	0
Principal and redemption premium payments on debt	0	0	0
Intercompany transfers	-3,156	13,684	17,537
Other financing activities	0	0	0
Increase (Decrease) in Cash and Cash Equivalents	-50	0	0
Beginning Cash and Cash Equivalents	50	50	50
Ending Cash and Cash Equivalents	0	50	50
Intercompany Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Cash flows from operating activities	0	0	0
Cash flows from investing activities:
Additions to oil and gas properties, including acquisitions	0	0	0
Additions to furniture, fixtures and other	0	0	0
Proceeds from sale of properties and other investing activities	0	0	0
Intercompany Transfers Investing Activities	-3,156
Cash flows from financing activities:
Proceeds from debt	0	0	0
Principal and redemption premium payments on debt	0	0	0
Intercompany transfers	3,156	0	0
Other financing activities	0	0	0
Increase (Decrease) in Cash and Cash Equivalents	0	0	0
Beginning Cash and Cash Equivalents	0	0	0
Ending Cash and Cash Equivalents	$0	$0	$0