Ranger Oil (ROCC) 10-Q 12 May 14 2014 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2014	2-May-14
Document Documentand Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	31-Mar-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q1	'
Trading Symbol	'PVA	'
Entity Registrant Name	'PENN VIRGINIA CORP	'
Entity Central Index Key	'0000077159	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	65,596,359

CONDENSED_CONSOLIDATED_STATEME

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Revenues	'	'
Crude oil	$105,576	$63,058
Natural gas liquids (NGLs)	9,373	7,127
Natural gas	18,203	12,039
Gain (loss) on sales of property and equipment, net	56,826	-549
Other, net	-113	1,523
Total revenues	189,865	83,198
Operating expenses	'	'
Lease operating	10,404	7,805
Gathering, processing and transportation	2,961	3,579
Production and ad valorem taxes	7,305	5,959
General and administrative	16,688	10,943
Exploration	8,636	6,295
Depreciation, depletion and amortization	72,187	51,576
Total operating expenses	118,181	86,157
Operating income (loss)	71,684	-2,959
Other income (expense)	'	'
Interest expense	-22,534	-14,479
Derivatives	-15,662	-7,761
Other	1	27
Income (loss) before income taxes	33,489	-25,172
Income tax (expense) benefit	-14,264	8,789
Net income (loss)	19,225	-16,383
Preferred stock dividends	-1,722	-1,725
Net income (loss) attributable to common shareholders - Diluted	$17,503	($18,108)
Net income (loss) per share:	'	'
Basic (in dollars per share)	$0.27	($0.33)
Diluted (in dollars per share)	$0.22	($0.33)
Weighted average shares outstanding - basic	65,611	55,341
Weighted average shares outstanding - diluted	85,744	55,341

CONDENSED_CONSOLIDATED_STATEME1

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Statement of Comprehensive Income [Abstract]	'	'
Net income (loss)	$19,225	($16,383)
Other comprehensive income:	'	'
Change in pension and postretirement obligations, net of tax of $13 and $10 in 2014 and 2013	25	19
Total Other Comprehensive Income (Loss), Net of Tax	25	19
Comprehensive income (loss)	$19,250	($16,364)

CONDENSED_CONSOLIDATED_STATEME2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Statement of Comprehensive Income [Abstract]	'	'
Change in pension and postretirement obligations, net of tax	$13	$10

CONDENSED_CONSOLIDATED_BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets	'	'
Cash and cash equivalents	$9,554	$23,474
Accounts receivable, net of allowance for doubtful accounts	167,190	194,403
Derivative assets	65	3,830
Deferred Tax Assets, Net of Valuation Allowance, Current	6,065	6,065
Other current assets	5,372	5,924
Total current assets	188,246	233,696
Property and equipment, net (successful efforts method)	2,312,003	2,237,304
Derivative assets	1,974	1,552
Other assets	33,710	34,535
Total assets	2,535,933	2,507,087
Current liabilities	'	'
Accounts payable and accrued liabilities	238,212	248,004
Derivative liabilities	19,403	10,141
Accrued Income Taxes, Current	200	0
Total current liabilities	257,815	258,145
Other liabilities	45,045	33,386
Derivative liabilities	0	0
Deferred income taxes	159,830	145,752
Long-term debt	1,265,000	1,281,000
Commitments and contingencies (Note 11)	'	'
Shareholders’ equity:	'	'
Preferred stock of $100 par value – 100,000 shares authorized; 11,481 and 11,500 shares issued as of March 31, 2014 and December 31, 2013, respectively, with a redemption value of $10,000 per share	1,148	1,150
Common stock of $0.01 par value – 128,000,000 shares authorized; 65,581,512 and 65,306,748 shares issued as of March 31, 2014 and December 31, 2013, respectively	468	466
Paid-in capital	893,262	891,351
Accumulated deficit	-86,677	-104,180
Deferred compensation obligation	2,897	2,792
Accumulated other comprehensive income	292	267
Treasury stock – 239,065 and 233,063 shares of common stock, at cost, as of March 31, 2014 and December 31, 2013, respectively	-3,147	-3,042
Total shareholders’ equity	808,243	788,804
Total liabilities and shareholders’ equity	$2,535,933	$2,507,087

CONDENSED_CONSOLIDATED_BALANCE1

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Mar. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]	'	'
Preferred stock, par value	$100	$100
Preferred stock, shares authorized	100,000	100,000
Preferred stock, issued	11,481	11,500
Preferred stock, redemption value per share (in dollars per share)	$10,000	$10,000
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	128,000,000	128,000,000
Common stock, shares issued	65,581,512	65,306,748
Treasury stock, shares	239,065	233,063

CONDENSED_CONSOLIDATED_STATEME3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Cash flows from operating activities	'	'
Net income (loss)	$19,225	($16,383)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:	'	'
Depreciation, depletion and amortization	72,187	51,576
Accretion of firm transportation obligation	354	207
Derivative contracts:	'	'
Net losses	15,662	7,761
Cash settlements, net	-3,057	3,557
Deferred income tax expense (benefit)	14,064	-8,789
(Gain) loss on sales of assets, net	-56,826	549
Non-cash exploration expense	3,294	5,262
Non-cash interest expense	1,012	946
Share-based compensation (equity-classified)	825	1,085
Other, net	206	81
Changes in operating assets and liabilities	-386	-237
Net cash provided by operating activities	66,560	45,615
Cash flows from investing activities	'	'
Capital expenditures - property and equipment	-159,804	-85,973
Proceeds from sales of assets, net	95,964	878
Net cash used in investing activities	-63,840	-85,095
Cash flows from financing activities	'	'
Proceeds from revolving credit facility borrowings	85,000	38,000
Repayment of revolving credit facility borrowings	-101,000	0
Dividends paid on preferred stock	-1,725	-1,687
Other, net	1,085	-61
Net cash (used in) provided by financing activities	-16,640	36,252
Net decrease in cash and cash equivalents	-13,920	-3,228
Cash and cash equivalents - beginning of period	23,474	17,650
Cash and cash equivalents - end of period	9,554	14,422
Cash paid for:	'	'
Interest	1,025	340
Income taxes (net of refunds received)	$0	$0

Organization

Organization	3 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]	'
Organization	'
	Organization
	Penn Virginia Corporation (“Penn Virginia,” the “Company,” “we,” “us” or “our”) is an independent oil and gas company engaged in the exploration, development and production of oil, natural gas liquids (“NGLs”) and natural gas in various onshore regions of the United States. Our current operations consist primarily of the drilling of unconventional horizontal development wells in shale formations and are currently concentrated in the Eagle Ford Shale in South Texas. We also have operations in the Granite Wash in Oklahoma, the Haynesville Shale and Cotton Valley in East Texas and the Selma Chalk in Mississippi.

Basis_of_Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2014
Accounting Policies [Abstract]	'
Basis of Presentation	'
	Basis of Presentation
	Our unaudited Condensed Consolidated Financial Statements include the accounts of Penn Virginia and all of our subsidiaries. Intercompany balances and transactions have been eliminated. Our Condensed Consolidated Financial Statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). Preparation of these statements involves the use of estimates and judgments where appropriate. In the opinion of management, all adjustments, consisting of normal recurring accruals, considered necessary for a fair presentation of our Condensed Consolidated Financial Statements have been included. Our Condensed Consolidated Financial Statements should be read in conjunction with the Consolidated Financial Statements and Notes included in our Annual Report on Form 10-K for the year ended December 31, 2013. Operating results for the three months ended March 31, 2014 are not necessarily indicative of the results that may be expected for the year ending December 31, 2014. Certain amounts for the 2013 period have been reclassified to conform to the current year presentation.
	Management has evaluated all activities of the Company, through the date upon which our Condensed Consolidated Financial Statements were issued, and concluded that no subsequent events have occurred that would require recognition in our Condensed Consolidated Financial Statements or disclosure in the Notes to Condensed Consolidated Financial Statements.

Acquisitions_and_Divestitures

Acquisitions and Divestitures	3 Months Ended
	Mar. 31, 2014
Acquisitions and Divestitures [Abstract]	'
Acquisitions and Divestitures	'
	Acquisitions and Divestitures
	Acquisitions
	On April 24, 2013 (the “Acquisition Date”), we acquired producing properties and undeveloped leasehold interests in the Eagle Ford Shale play (the “EF Acquisition”). The EF Acquisition was originally valued at $401 million with an effective date of January 1, 2013 (the “Effective Date”). On the Acquisition Date we paid approximately $380 million in cash, including approximately $19 million of initial purchase price adjustments related to the period from the Effective Date to the closing, and issued to the seller 10 million shares of our common stock (the “Shares”) with a fair value of $4.23 per share. Shortly after the closing, certain of our joint interest partners exercised preferential rights related to the EF Acquisition. We received approximately $21 million from the exercise of these rights, which was recorded as a decrease to our purchase price for the EF Acquisition.
	Since December 2013, we have been involved in an arbitration with Magnum Hunter Resources Corporation (“MHR”), the seller in our EF Acquisition. The arbitration relates to disputes we have with MHR regarding contractual adjustments to the purchase price for the EF Acquisition and suspense funds that we believe MHR is obligated to transfer to us. MHR has indicated that it owes us approximately $26.5 million; we believe the amount is higher. Both parties submitted rebuttals to initial briefs on March 3, 2014 and submitted additional responses and replies on April 4, 2014. We expect the arbitration to be resolved in the second quarter of 2014.
	We accounted for the EF Acquisition by applying the acquisition method of accounting as of the Acquisition Date. The initial accounting for the EF Acquisition as presented below is based upon preliminary information and was not complete, due primarily to the aforementioned arbitration, as of the date our Condensed Consolidated Financial Statements were issued.
	The following table represents the preliminary fair values assigned to the net assets acquired as of the closing and the consideration paid:
	Assets
	Oil and gas properties - proved	$	277,888
	Oil and gas properties - unproved	119,709
	Accounts receivable, net	97,145
	Other assets	2,068
		496,810
	Liabilities
	Accounts payable and accrued expenses	94,771
	Other liabilities	1,500
		96,271
	Net assets acquired	$	400,539
	Cash, net of amounts received for preferential rights	$	358,239
	Fair value of the Shares issued to MHR	42,300
	Consideration paid	$	400,539
	The fair values of the acquired net assets were measured using valuation techniques that convert future cash flows to a single discounted amount. Significant inputs to valuation of oil and natural gas properties include estimates of: (i) reserves, (ii) future operating and development costs, (iii) future commodity prices, (iv) future cash flows and (v) a market-based weighted-average cost of capital. Because many of these inputs are not observable, we have classified the initial fair value estimates as level 3 inputs as that term is defined in U.S. GAAP.
	The results of operations attributable to the EF Acquisition have been included in our Condensed Consolidated Financial Statements from the Acquisition Date. The following table presents unaudited summary pro forma financial information for the period presented assuming the EF Acquisition and the related financing occurred as of January 1, 2012. The pro forma financial information does not purport to represent what our results of operations would have been if the EF Acquisition had occurred as of this date or the results of operations for any future periods.
		Three Months
		Ended
		31-Mar-13
	Total revenues	$	109,064
	Net loss attributable to common shareholders	$	(15,204	)
	Loss per share - basic and diluted	$	(0.23	)
	Divestitures
	In December 2013, we entered into an agreement to sell our natural gas gathering assets in South Texas. Concurrent with the sale, we entered into a long-term agreement in which the buyer will provide us natural gas gathering and compression services for a substantial portion of our natural gas and NGL production in the South Texas region. The transaction closed in January 2014 and resulted in the receipt of proceeds of approximately $96 million. We realized a gain of $67.3 million of which $56.7 million was recognized at the closing of the transaction and the remaining $10.6 million was deferred and is being recognized over a twenty-five year period. We amortized $0.1 million of the deferred gain during the three months ended March 31, 2014. As of March 31, 2014, $0.4 million of the remaining deferred gain is included as a component of Accounts payable and accrued expenses and $10.1 million, representing the noncurrent portion, is included as a component of Other liabilities on our Condensed Consolidated Balance Sheets.

Accounts_Receivable_and_Major_

Accounts Receivable and Major Customers	3 Months Ended
	Mar. 31, 2014
Receivables [Abstract]	'
Accounts Receivable and Major Customers	'
	Accounts Receivable and Major Customers
	The following table summarizes our accounts receivable by type as of the dates presented:
		As of
		March 31,			December 31,
		2014			2013
	Customers	$	92,612		$	93,288
	Joint interest partners	43,860			76,199
	Other 1	31,340			25,538
		167,812			195,025
	Less: Allowance for doubtful accounts	(622		)	(622		)
		$	167,190		$	194,403
	______________________
	1 Comprised substantially of amounts due from the seller and other parties for purchase price adjustments attributable to the EF Acquisition.
	For the three months ended March 31, 2014, four customers accounted for $89.5 million, or approximately 67%, of our consolidated product revenues. The revenues generated from these customers during the three months ended March 31, 2014 were $38.8 million, $17.4 million, $17.2 million and $16.1 million or 29%, 13%, 13% and 12% of the consolidated total, respectively. As of March 31, 2014, $40.0 million, or approximately 43% of our consolidated accounts receivable from customers was related to these customers. For the three months ended March 31, 2013, four customers accounted for $46.2 million, or approximately 56% of our consolidated product revenues. The revenues generated from these customers during the three months ended March 31, 2013 were $16.1 million, $10.9 million, $10.6 million and $8.6 million or approximately 20%, 13%, 13% and 10% of the consolidated total, respectively. As of December 31, 2013, $36.9 million, or approximately 40% of our consolidated accounts receivable from customers, was related to these customers. No significant uncertainties exist related to the collectability of amounts owed to us by any of these customers.

Derivative_Instruments

Derivative Instruments	3 Months Ended
	Mar. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Instruments	'
	Derivative Instruments
	We utilize derivative instruments to mitigate our financial exposure to crude oil and natural gas price volatility and, from time to time, the volatility in interest rates attributable to our debt instruments. Our derivative instruments are not formally designated as hedges.
	Commodity Derivatives
	We utilize collars, swaps and swaptions, which are placed with financial institutions that we believe are acceptable credit risks, to hedge against the variability in cash flows associated with anticipated sales of our future oil and gas production. While the use of derivative instruments limits the risk of adverse price movements, such use may also limit future revenues from favorable price movements.
	The counterparty to a collar or swap contract is required to make a payment to us if the settlement price for any settlement period is below the floor or swap price for such contract. We are required to make a payment to the counterparty if the settlement price for any settlement period is above the ceiling or swap price for such contract. Neither party is required to make a payment to the other party if the settlement price for any settlement period is equal to or greater than the floor price and equal to or less than the ceiling price for such contract. A swaption contract gives our counterparties the option to enter into a fixed price swap with us at a future date. If the forward commodity price for the term of the swaption is higher than or equal to the swaption strike price on the exercise date, the counterparty will exercise its option to enter into a fixed price swap at the swaption strike price for the term of the swaption, at which point the contract functions as a fixed price swap. If the forward commodity price for the term of the swaption is lower than the swaption strike price on the exercise date, the option expires and no fixed price swap is in effect.
	We determine the fair values of our commodity derivative instruments based on discounted cash flows derived from third-party quoted forward prices for NYMEX Henry Hub gas and West Texas Intermediate crude oil closing prices as of the end of the reporting period. The discounted cash flows utilize discount rates adjusted for the credit risk of our counterparties if the derivative is in an asset position and our own credit risk if the derivative is in a liability position.
	The following table sets forth our commodity derivative positions as of March 31, 2014:
				Average
				Volume Per			Weighted Average Price								Fair Value
		Instrument		Day			Floor/Swap				Ceiling				Asset				Liability
	Crude Oil:			(barrels)			($/barrel)
	Second quarter 2014	Collars		2,500			$	92			$	99.46			$	—			$	740
	Third quarter 2014	Collars		2,000			$	90			94.33				—				827
	Fourth quarter 2014	Collars		2,000			$	90			94.33				—				420
	First quarter 2015	Collars		4,000			$	87.5			94.66				—				278
	Second quarter 2015	Collars		4,000			$	87.5			94.66				276				—
	Third quarter 2015	Collars		3,000			$	86.67			94.73				507				—
	Fourth quarter 2015	Collars		3,000			$	86.67			94.73				766				—
	Second quarter 2014	Swaps		8,500			$	94							—				4,984
	Third quarter 2014	Swaps		10,000			$	93.21							342				4,410
	Fourth quarter 2014	Swaps		10,000			$	93.21							709				2,417
	First quarter 2015	Swaps		7,000			$	90.79							—				1,440
	Second quarter 2015	Swaps		7,000			$	90.79							—				447
	Third quarter 2015	Swaps		6,000			$	90.45							150				—
	Fourth quarter 2015	Swaps		6,000			$	90.45							722				—
	First quarter 2015	Swaptions		1,000			$	88							—				535
	Second quarter 2015	Swaptions		1,000			$	88							—				534
	Third quarter 2015	Swaptions		1,000			$	88							—				534
	Fourth quarter 2015	Swaptions		1,000			$	88							—				534
	Natural Gas:			(in MMBtu)			($/MMBtu)
	Second quarter 2014	Swaps		15,000			$	4.1							—				474
	Third quarter 2014	Swaps		15,000			$	4.1							—				450
	Fourth quarter 2014	Swaps		5,000			$	4.5							—				2
	First quarter 2015	Swaps		5,000			$	4.5							—				49
	Settlements to be paid in subsequent period														—				1,761
	Interest Rate Swaps
	As of March 31, 2014, we had no interest rate derivative instruments outstanding.
	Financial Statement Impact of Derivatives
	The impact of our derivatives activities on income is included in the Derivatives caption on our Condensed Consolidated Statements of Operations. The following table summarizes the effects of our derivative activities for the periods presented:
						Three Months Ended
						March 31,
						2014				2013
	Impact by contract type:
	Commodity contracts					$	(15,662	)		$	(7,761	)
	Interest rate contracts					—				—
						$	(15,662	)		$	(7,761	)
	Cash settlements and gains (losses):
	Cash (paid) received for:
	Commodity contract settlements					$	(3,057	)		$	3,557
	Interest rate contract settlements					—				—
						(3,057		)		3,557
	Losses attributable to:
	Commodity contracts					(12,605		)		(11,318		)
	Interest rate contracts					—				—
						(12,605		)		(11,318		)
						$	(15,662	)		$	(7,761	)
	The effects of derivative gains and (losses) and cash settlements of our commodity and interest rate derivatives are reported as adjustments to reconcile net income (loss) to net cash provided by operating activities. These items are recorded in the Derivative contracts section of our Condensed Consolidated Statements of Cash Flows under the Net losses and Cash settlements, net captions.
	The following table summarizes the fair values of our derivative instruments as well as the locations of these instruments, on our Condensed Consolidated Balance Sheets as of the dates presented:
					Fair Values as of
					31-Mar-14								31-Dec-13
					Derivative				Derivative				Derivative				Derivative
	Type		Balance Sheet Location		Assets				Liabilities				Assets				Liabilities
	Commodity contracts		Derivative assets/liabilities - current		$	65			$	19,403			$	3,830			$	10,141
Interest rate contracts		Derivative assets/liabilities - current		—				—				—				—
				65				19,403				3,830				10,141
Commodity contracts		Derivative assets/liabilities - noncurrent		1,974				—				1,552				—
Interest rate contracts		Derivative assets/liabilities - noncurrent		—				—				—				—
				1,974				—				1,552				—
				$	2,039			$	19,403			$	5,382			$	10,141
As of March 31, 2014, we reported a commodity derivative asset of $2.0 million. The contracts associated with this position are with five counterparties, all of which are investment grade financial institutions, and are substantially concentrated with three of those counterparties. This concentration may impact our overall credit risk, either positively or negatively, in that these counterparties may be similarly affected by changes in economic or other conditions. We have neither paid to, nor received from, our counterparties any cash collateral in connection with our derivative positions. No significant uncertainties exist related to the collectability of amounts that may be owed to us by these counterparties.

Property_and_Equipment

Property and Equipment	3 Months Ended
	Mar. 31, 2014
Property, Plant and Equipment [Abstract]	'
Property and Equipment	'
	Property and Equipment
	The following table summarizes our property and equipment as of the dates presented:
		As of
		March 31,			December 31,
		2014			2013
	Oil and gas properties:
	Proved	$	462,404		$	460,255
	Unproved	101,426			101,520
	Total oil and gas properties	563,830			561,775
	Other property and equipment:
	Wells equipment and facilities	2,738,102			2,593,700
	Support equipment	21,857			21,513
	Total other property and equipment	2,759,959			2,615,213
		3,323,789			3,176,988
	Accumulated depreciation, depletion and amortization	(1,011,786		)	(939,684		)
		$	2,312,003		$	2,237,304

LongTerm_Debt

Long-Term Debt	3 Months Ended
	Mar. 31, 2014
Debt Disclosure [Abstract]	'
Long-Term Debt	'
	Long-Term Debt
	The following table summarizes our long-term debt as of the dates presented:
		As of
		March 31,		December 31,
		2014		2013
	Revolving credit facility	$	190,000	$	206,000
	Senior notes due 2019	300,000		300,000
	Senior notes due 2020	775,000		775,000
		$	1,265,000	$	1,281,000
	Revolving Credit Facility
	The revolving credit facility (the “Revolver”) provides for a $400 million revolving commitment. The Revolver has an accordion feature that allows us to increase the commitment by up to an additional $200 million upon receiving additional commitments from one or more lenders. The Revolver also includes a $20 million sublimit for the issuance of letters of credit. The Revolver is governed by a borrowing base calculation, which is re-determined semi-annually, and the availability under the Revolver may not exceed the lesser of the aggregate commitments and the borrowing base. In May 2014, the borrowing base was increased from $425 million to $475 million, due primarily to our continued development in the Eagle Ford Shale. The next semi-annual redetermination is scheduled for November 2014. The Revolver is available to us for general purposes including working capital, capital expenditures and acquisitions. The Revolver matures in September 2017. We had letters of credit of $1.7 million outstanding as of March 31, 2014. As of March 31, 2014, our available borrowing capacity under the Revolver was $208.3 million.
	Borrowings under the Revolver bear interest, at our option, at either (i) a rate derived from the London Interbank Offered Rate, as adjusted for statutory reserve requirements for Eurocurrency liabilities (“Adjusted LIBOR”), plus an applicable margin (ranging from 1.500% to 2.500%) or (ii) the greater of (a) the prime rate, (b) the federal funds effective rate plus 0.5% or (c) the one-month Adjusted LIBOR plus 1.0%, and, in each case, plus an applicable margin (ranging from 0.500% to 1.500%). The applicable margin is determined based on the ratio of our outstanding borrowings to the available Revolver capacity. As of March 31, 2014, the actual interest rate on the outstanding borrowings under the Revolver was 1.9375% which is derived from an Adjusted LIBOR rate of 0.1875% plus an applicable margin of 1.75%. Commitment fees are charged at 0.375% to 0.500% on the undrawn portion of the Revolver depending on our ratio of outstanding borrowings to the available Revolver capacity. As of March 31, 2014, commitment fees were being charged at a rate of 0.375%.
	The Revolver is guaranteed by Penn Virginia and all of our material subsidiaries (the “Guarantor Subsidiaries”). The obligations under the Revolver are secured by a first priority lien on substantially all of our proved oil and gas reserves and a pledge of the equity interests in the Guarantor Subsidiaries.
	The Revolver includes both current ratio and leverage ratio financial covenants. The current ratio is defined in the Revolver to include, among other things, adjustments for undrawn availability and may not be less than 1.0 to 1.0. The ratio of total net debt to EBITDAX, a non-GAAP financial measure defined in the Revolver, may not exceed 4.5 to 1.0 through June 30, 2014, 4.25 to 1.0 through December 31, 2014 and then 4.0 to 1.0 through maturity.
	2019 Senior Notes
	The 7.25% Senior Notes due 2019 (the “2019 Senior Notes”), which were issued at par in April 2011, bear interest at an annual rate of 7.25% payable on April 15 and October 15 of each year. Beginning in April 2015, we may redeem all or part of the 2019 Senior Notes at a redemption price starting at 103.625% of the principal amount and reducing to 100% in June 2017 and thereafter. The 2019 Senior Notes are senior to our existing and future subordinated indebtedness and are subordinated to all of our secured indebtedness, including the Revolver, to the extent of the collateral securing that indebtedness. The obligations under the 2019 Senior Notes are fully and unconditionally guaranteed by the Guarantor Subsidiaries.
	2020 Senior Notes
	The 2020 Senior Notes due 2020 (the “2020 Senior Notes”), which were issued at par in April 2013, bear interest at an annual rate of 8.5% payable on June 15 and December 15 of each year. The 2020 Senior Notes are senior to our existing and future subordinated indebtedness and are subordinated to all of our secured indebtedness, including the Revolver, to the extent of the collateral securing that indebtedness. The obligations under the 2020 Senior Notes are fully and unconditionally guaranteed by the Guarantor Subsidiaries.
	The guarantees provided by Penn Virginia, which is the parent company, and the Guarantor Subsidiaries under the Revolver and the senior indebtedness described above are full and unconditional and joint and several. Substantially all of our consolidated assets are held by the Guarantor Subsidiaries. The parent company and its non-guarantor subsidiaries have no material independent assets or operations. There are no significant restrictions on the ability of the parent company or any of the Guarantor Subsidiaries to obtain funds through dividends or other means, including advances and intercompany notes, among others.

Income_Taxes_Notes

Income Taxes (Notes)	3 Months Ended
	Mar. 31, 2014
Income Tax Disclosure [Abstract]	'
Income Tax Disclosure [Text Block]	'
	Income Taxes
	We recognized income tax expense for the three months ended March 31, 2014 at an effective tax rate of 42.6%. The effective tax rate reflects the adverse effect of losses incurred in certain jurisdictions for which we may not realize a tax benefit and have therefore recorded a valuation allowance against the related deferred tax assets. Such losses reduce our taxable income without a corresponding reduction in our income tax expense, and therefore increase our effective tax rate. Additionally, our effective tax rate is also adversely impacted by the amount of losses in certain subsidiaries relative to taxable income of the Company. Due to the loss incurred during the three months ended March 31, 2013, we recognized an income tax benefit at an effective tax rate of 34.9%. The income tax benefit included the effect of deferred tax asset valuation allowance due primarily to the inability to recognize tax benefits for certain state net operating losses.

Additional_Balance_Sheet_Detai

Additional Balance Sheet Detail	3 Months Ended
	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Additional Balance Sheet Detail	'
	Additional Balance Sheet Detail
	The following table summarizes components of selected balance sheet accounts as of the dates presented:
		As of
		March 31,		December 31,
		2014		2013
	Other current assets:
	Tubular inventory and well materials	$	1,965	$	2,271
	Prepaid expenses	3,407		3,653
		$	5,372	$	5,924
	Other assets:
	Debt issuance costs	$	29,227	$	30,239
	Assets of supplemental employee retirement plan (“SERP”)	3,815		3,734
	Other	668		562
		$	33,710	$	34,535
	Accounts payable and accrued liabilities:
	Trade accounts payable	$	75,235	$	120,278
	Drilling and other lease operating costs	62,620		51,529
	Royalties	41,860		39,929
	Production and franchise taxes	1,929		5,338
	Compensation - related	7,951		8,584
	Interest	37,833		15,718
	Preferred stock dividends	1,722		1,725
	Other	9,062		4,903
		$	238,212	$	248,004
	Other liabilities:
	Deferred gain on sale of assets	$	10,095	$	—
	Firm transportation obligation	12,964		13,245
	Asset retirement obligations (“AROs”)	6,537		6,437
	Defined benefit pension obligations	1,523		1,579
	Postretirement health care benefit obligations	1,071		1,023
	Deferred compensation - SERP obligations and other	4,089		3,883
	Other	8,766		7,219
		$	45,045	$	33,386

Fair_Value_Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Fair Value Measurements
	We apply the authoritative accounting provisions for measuring fair value of both our financial and nonfinancial assets and liabilities. Fair value is an exit price representing the expected amount we would receive upon the sale of an asset or that we would expect to pay to transfer a liability in an orderly transaction with market participants at the measurement date.
	Our financial instruments that are subject to fair value disclosure consist of cash and cash equivalents, accounts receivable, accounts payable, derivatives and long-term debt. As of March 31, 2014, the carrying values of all of these financial instruments, except the portion of long-term debt with fixed interest rates, approximated fair value.
	The following table summarizes the fair value of our long-term debt with fixed interest rates, which is estimated based on the published market prices for these debt obligations, as of the dates presented:
		As of
		31-Mar-14								31-Dec-13
		Fair				Carrying				Fair				Carrying
		Value				Value				Value				Value
	Senior Notes due 2019	$	318,000			$	300,000			$	307,500			$	300,000
	Senior Notes due 2020	862,188				775,000				837,969				775,000
		$	1,180,188			$	1,075,000			$	1,145,469			$	1,075,000
	Recurring Fair Value Measurements
	Certain financial assets and liabilities are measured at fair value on a recurring basis in our Condensed Consolidated Balance Sheets. The following tables summarize the valuation of those assets and liabilities as of the dates presented:
			As of March 31, 2014
			Fair Value				Fair Value Measurement Classification
	Description		Measurement				Level 1				Level 2				Level 3
	Assets:
	Commodity derivative assets - current		$	65			$	—			$	65			$	—
	Commodity derivative assets - noncurrent		1,974				—				1,974				—
	Assets of SERP		3,815				3,815				—				—
	Liabilities:
	Commodity derivative liabilities - current		(19,403		)		—				(19,403		)		—
	Commodity derivative liabilities - noncurrent		—				—				—				—
	Deferred compensation - SERP obligations		(4,084		)		(4,084		)		—				—
			As of December 31, 2013
			Fair Value				Fair Value Measurement Classification
	Description		Measurement				Level 1				Level 2				Level 3
	Assets:
	Commodity derivative assets - current		$	3,830			$	—			$	3,830			$	—
	Commodity derivative assets - noncurrent		1,552				—				1,552				—
	Assets of SERP		3,734				3,734				—				—
	Liabilities:
	Commodity derivative liabilities - noncurrent		(10,141		)		—				(10,141		)		—
	Deferred compensation - SERP obligations		(3,879		)		(3,879		)		—				—
	Changes in economic conditions or model-based valuation techniques may require the transfer of financial instruments from one level of the fair value hierarchy to another level. In such instances, the transfer is deemed to have occurred at the beginning of the quarterly period in which the event or change in circumstances that caused the transfer occurred. There were no transfers during the three months ended March 31, 2014 and 2013.
	We used the following methods and assumptions to estimate fair values for the financial assets and liabilities described below:
	•	Commodity derivatives: We determine the fair values of our commodity derivative instruments based on discounted cash flows derived from third-party quoted forward prices for West Texas Intermediate crude oil and NYMEX Henry Hub gas closing prices as of the end of the reporting periods. We generally use the income approach, using valuation techniques that convert future cash flows to a single discounted value. Each of these is a level 2 input.
	•	Assets of SERP: We hold various publicly traded equity securities in a Rabbi Trust as assets for funding certain deferred compensation obligations. The fair values are based on quoted market prices, which are level 1 inputs.
	•	Deferred compensation - SERP obligations: Certain of our deferred compensation obligations are ultimately to be settled in cash based on the underlying fair value of certain assets, including those held in the Rabbi Trust. The fair values are based on quoted market prices, which are level 1 inputs.
	Non-Recurring Fair Value Measurements
	The most significant non-recurring fair value measurements utilized in the preparation of our Condensed Consolidated Financial Statements are those attributable to the recognition and measurement of net assets acquired, the recognition and measurement of asset impairments and the initial determination of AROs. The factors used to determine fair value for purposes of recognizing and measuring net assets acquired and asset impairments include, but are not limited to, estimates of proved and probable reserves, future commodity prices, indicative sales prices for properties, the timing of future production and capital expenditures and a discount rate commensurate with the risk reflective of the lives remaining for the respective oil and gas properties. Because these significant fair value inputs are typically not observable, we have categorized the amounts as level 3 inputs.
	The determination of the fair value of AROs is based upon regional market and facility specific information. The amount of an ARO and the costs capitalized represent the estimated future cost to satisfy the abandonment obligation using current prices that are escalated by an assumed inflation factor after discounting the future cost back to the date that the abandonment obligation was incurred using a rate commensurate with the risk, which approximates our cost of funds. Because these significant fair value inputs are typically not observable, we have categorized the initial estimates as level 3 inputs.

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	Commitments and Contingencies
	Drilling and Completion Commitments
	We have agreements to purchase oil and gas well drilling and well completion services from third parties with remaining terms of up to 14 months. The well drilling agreements include early termination provisions that would require us to pay penalties if we terminate the agreements prior to the end of their original terms. The amount of penalty is based on the number of days remaining in the contractual term. As of March 31, 2014, the penalty amount would have been $17.3 million if we had terminated our agreements on that date.
	Other Commitments
	We have entered into contracts that provide firm transportation capacity rights for specified volumes per day on various pipeline systems with terms that range from 1 to 15 years. The contracts require us to pay transportation demand charges regardless of the amount of pipeline capacity we use. We may sell excess capacity to third parties at our discretion.
	As discussed in Note 3, we entered into a long-term agreement that provides natural gas gathering and compression services for a substantial portion of our natural gas and NGL production in the South Texas region through 2038. The agreement requires us to make certain minimum fee payments regardless of the volume of natural gas and NGL production for the first three years of the term. The minimum fee requirements for 2014 through 2016 are $3.7 million, $4.2 million and $5.0 million, respectively.
	Legal and Regulatory
	We are involved, from time to time, in various legal proceedings arising in the ordinary course of business. While the ultimate results of these proceedings cannot be predicted with certainty, our management believes that these claims will not have a material effect on our financial position, results of operations or cash flows. During 2010, we established a $0.9 million reserve for a litigation matter pertaining to certain properties that remains outstanding as of March 31, 2014. In addition to the reserve for litigation, we maintain a suspense account which includes approximately $1.8 million representing the excess of revenues received over costs incurred attributable to these properties. As discussed in Note 3, we are involved in an arbitration with MHR in connection with our EF Acquisition. As of March 31, 2014, we also have AROs of approximately $6.5 million attributable to the plugging of abandoned wells.

Shareholders_Equity

Shareholders' Equity	3 Months Ended
	Mar. 31, 2014
Equity [Abstract]	'
Shareholders' Equity	'
	Shareholders’ Equity
	The following tables summarize the components of our shareholders’ equity and the changes therein as of and for the three months ended March 31, 2014 and 2013:
		As of												As of
		December 31,						Dividends			All Other			March 31,
		2013			Net Loss			Declared 1			Changes 2			2014
	Preferred stock 3	$	1,150		$	—		$	—		$	(2	)	$	1,148
	Common stock 3	466			—			—			2			468
	Paid-in capital 3	891,351			—			—			1,911			893,262
	Retained earnings	(104,180		)	19,225			(1,722		)	—			(86,677		)
	Deferred compensation obligation	2,792			—			—			105			2,897
	Accumulated other comprehensive income 4	267			—			—			25			292
	Treasury stock	(3,042		)	—			—			(105		)	(3,147		)
		$	788,804		$	19,225		$	(1,722	)	$	1,936		$	808,243
		As of												As of
		December 31,						Dividends			All Other			March 31,
		2012			Net Loss			Declared 1			Changes 2			2013
	Preferred stock	$	1,150		$	—		$	—		$	—		$	1,150
	Common stock	364			—			—			1			365
	Paid-in capital	849,046			—			—			664			849,710
	Retained earnings	45,790			(16,383		)	(1,725		)	—			27,682
	Deferred compensation obligation	3,111			—			—			65			3,176
	Accumulated other comprehensive loss 4	(982		)	—			—			19			(963		)
	Treasury stock	(3,363		)	—			—			(64		)	(3,427		)
		$	895,116		$	(16,383	)	$	(1,725	)	$	685		$	877,693
	_______________________
	1 Includes dividends of $150.00 per share of 6% Convertible Perpetual Preferred Stock (the “6% Preferred Stock”).
	2 Includes equity-classified share-based compensation of $825 and $1,085 for the three months ended March 31, 2014 and 2013.
	3 A total of 19.5 shares, or 1,950 depositary shares, of 6% Preferred Stock were converted into 32,500 shares of our common stock during the three months ended March 31, 2014.
	4 The Accumulated other comprehensive income (loss) (“AOCI”) is entirely attributable to our defined benefit pension and postretirement health care plans. The changes in the balance of AOCI for the three months ended March 31, 2014 and 2013 represent reclassifications from AOCI to net periodic benefit expense, a component of General and administrative expenses, of $38 and $29 and are presented above net of taxes of $13 and $10.

ShareBased_Compensation

Share-Based Compensation	3 Months Ended
	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Share-Based Compensation	'
	Share-Based Compensation
	The Penn Virginia Corporation 2013 Amended and Restated Long-Term Incentive Plan (the “LTI Plan”) permits the grant of incentive and nonqualified stock options, common stock, deferred common stock units, restricted stock and restricted stock units to our employees and directors. We recognize compensation expense related to our LTI Plan in the General and administrative caption on our Condensed Consolidated Statements of Operations.
	With the exception of performance-based restricted stock units (“PBRSUs”), all of the awards issued under our LTI Plan are classified as equity instruments because they result in the issuance of common stock on the date of grant, upon exercise or are otherwise payable in common stock upon vesting, as applicable. The compensation cost attributable to these awards is measured at the grant date and recognized over the applicable vesting period as a non-cash item of expense. Because the PBRSUs are payable in cash, they are considered liability-classified awards and are included in the Accounts payable and accrued liabilities (current portion) and Other liabilities (noncurrent portion) captions on our Condensed Consolidated Balance Sheets. Compensation cost associated with the PBRSUs is measured at the end of each reporting period and recognized based on the period of time that has elapsed during each of the individual performance periods.
	The following table summarizes our share-based compensation expense recognized for the periods presented:
		Three Months Ended
		March 31,
		2014		2013
	Equity-classified awards:
	Stock option awards	$	461	$	792
	Common, deferred and restricted stock and stock unit awards	364		293
		825		1,085
	Liability-classified awards	5,945		14
		$	6,770	$	1,099

Restructuring_and_Exit_Activit

Restructuring and Exit Activities	3 Months Ended
	Mar. 31, 2014
Restructuring and Related Activities [Abstract]	'
Restructuring and Exit Activities	'
	Restructuring and Exit Activities
	We have a contractual commitment for certain firm transportation capacity in the Appalachian region that expires in 2022 and, as a result of the sale of our natural gas assets in West Virginia, Kentucky and Virginia in 2012, we no longer have production to satisfy this commitment. We recognized an obligation in 2012 representing the liability for estimated discounted future net cash outflows over the remaining term of the contract. The activity summarized below includes contractual payments on our obligations as well as the recognition of accretion expense and adjustments associated with changes in estimates.
	The following table summarizes our restructuring and exit activity-related obligations and the changes therein for the periods presented:
		Three Months Ended
		March 31,
		2014			2013
	Balance at beginning of period	$	16,090		$	17,263
	Employee, office and other costs accrued, net	12			—
	Accretion of firm transportation obligation	354			207
	Cash payments, net	(650		)	(498		)
	Balance at end of period	$	15,806		$	16,972
	Restructuring charges are included in the General and administrative caption on our Condensed Consolidated Statements of Operations. The accretion of the firm transportation obligation, net of any recoveries from the periodic sale of our contractual capacity, is charged as an offset to Other revenue.
	The current portion of our restructuring and exit cost obligations is included in the Accounts payable and accrued liabilities caption and the noncurrent portion is included in the Other liabilities caption on our Condensed Consolidated Balance Sheets. As of March 31, 2014, $2.7 million of the total obligations are classified as current while the remaining $13.1 million are classified as noncurrent.

Interest_Expense

Interest Expense	3 Months Ended
	Mar. 31, 2014
Banking and Thrift [Abstract]	'
Interest Expense	'
	Interest Expense
	The following table summarizes the components of interest expense for the periods presented:
		Three Months Ended
		March 31,
		2014			2013
	Interest on borrowings and related fees	$	23,140		$	13,583
	Accretion of original issue discount 1	—			321
	Amortization of debt issuance costs	1,012			626
	Capitalized interest 2	(1,618		)	(51		)
		$	22,534		$	14,479
	_____________________
	1 Represents accretion of original issue discount attributable to the 10.375% Senior Notes due 2016 that were retired in 2013.
	2 The increase in capitalized interest in 2014 is attributable to a significant increase in qualifying activities that are in process to bring our Eagle Ford Shale unproved and proved undeveloped properties, including those acquired in the EF Acquisition, into production.

Earnings_per_Share

Earnings per Share	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Earnings per Share	'
	Earnings per Share
	The following table provides a reconciliation of the components used in the calculation of basic and diluted earnings per share for the periods presented:
		Three Months Ended
		March 31,
		2014			2013
	Net income (loss)	$	19,225		$	(16,383	)
	Less: Preferred stock dividends	(1,722		)	(1,725		)
	Net income (loss) attributable to common shareholders - Basic	17,503			(18,108		)
	Add: Preferred stock dividends	1,722			—
	Net income (loss) attributable to common shareholders - Diluted	$	19,225		$	(18,108	)
	Weighted-average shares - Basic	65,611			55,341
	Effect of dilutive securities 1	20,133			—
	Weighted-average shares - Diluted	85,744			55,341
	_______________________
	1 For the three months ended March 31, 2013, approximately 19.2 million potentially dilutive securities, including the 6% Preferred Stock, stock options and restricted stock units, had the effect of being anti-dilutive and were excluded from the calculation of diluted earnings per common share.

Basis_of_Presentation_Policies

Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2014
Schedule of Policies [Line Items]	'
Basis of Presentation	'
	Basis of Presentation
	Our unaudited Condensed Consolidated Financial Statements include the accounts of Penn Virginia and all of our subsidiaries. Intercompany balances and transactions have been eliminated. Our Condensed Consolidated Financial Statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). Preparation of these statements involves the use of estimates and judgments where appropriate. In the opinion of management, all adjustments, consisting of normal recurring accruals, considered necessary for a fair presentation of our Condensed Consolidated Financial Statements have been included. Our Condensed Consolidated Financial Statements should be read in conjunction with the Consolidated Financial Statements and Notes included in our Annual Report on Form 10-K for the year ended December 31, 2013. Operating results for the three months ended March 31, 2014 are not necessarily indicative of the results that may be expected for the year ending December 31, 2014. Certain amounts for the 2013 period have been reclassified to conform to the current year presentation.
	Management has evaluated all activities of the Company, through the date upon which our Condensed Consolidated Financial Statements were issued, and concluded that no subsequent events have occurred that would require recognition in our Condensed Consolidated Financial Statements or disclosure in the Notes to Condensed Consolidated Financial Statements.
Fair Value Measurements	'
	We apply the authoritative accounting provisions for measuring fair value of both our financial and nonfinancial assets and liabilities. Fair value is an exit price representing the expected amount we would receive upon the sale of an asset or that we would expect to pay to transfer a liability in an orderly transaction with market participants at the measurement date.
Fair Value, Measurements, Recurring	'
Schedule of Policies [Line Items]	'
Fair Value Measurements	'
	We used the following methods and assumptions to estimate fair values for the financial assets and liabilities described below:
	•	Commodity derivatives: We determine the fair values of our commodity derivative instruments based on discounted cash flows derived from third-party quoted forward prices for West Texas Intermediate crude oil and NYMEX Henry Hub gas closing prices as of the end of the reporting periods. We generally use the income approach, using valuation techniques that convert future cash flows to a single discounted value. Each of these is a level 2 input.
	•	Assets of SERP: We hold various publicly traded equity securities in a Rabbi Trust as assets for funding certain deferred compensation obligations. The fair values are based on quoted market prices, which are level 1 inputs.
	•	Deferred compensation - SERP obligations: Certain of our deferred compensation obligations are ultimately to be settled in cash based on the underlying fair value of certain assets, including those held in the Rabbi Trust. The fair values are based on quoted market prices, which are level 1 inputs.
Fair Value, Measurements, Nonrecurring	'
Schedule of Policies [Line Items]	'
Fair Value Measurements	'
	The most significant non-recurring fair value measurements utilized in the preparation of our Condensed Consolidated Financial Statements are those attributable to the recognition and measurement of net assets acquired, the recognition and measurement of asset impairments and the initial determination of AROs. The factors used to determine fair value for purposes of recognizing and measuring net assets acquired and asset impairments include, but are not limited to, estimates of proved and probable reserves, future commodity prices, indicative sales prices for properties, the timing of future production and capital expenditures and a discount rate commensurate with the risk reflective of the lives remaining for the respective oil and gas properties. Because these significant fair value inputs are typically not observable, we have categorized the amounts as level 3 inputs.
	The determination of the fair value of AROs is based upon regional market and facility specific information. The amount of an ARO and the costs capitalized represent the estimated future cost to satisfy the abandonment obligation using current prices that are escalated by an assumed inflation factor after discounting the future cost back to the date that the abandonment obligation was incurred using a rate commensurate with the risk, which approximates our cost of funds. Because these significant fair value inputs are typically not observable, we have categorized the initial estimates as level 3 inputs.

Acquisition_and_Divestitures_T

Acquisition and Divestitures (Tables)	3 Months Ended
	Mar. 31, 2014
Acquisitions and Divestitures [Abstract]	'
Business Acquisition, Purchase Price Allocation [Table Text Block]	'
	The following table represents the preliminary fair values assigned to the net assets acquired as of the closing and the consideration paid:
	Assets
	Oil and gas properties - proved	$	277,888
	Oil and gas properties - unproved	119,709
	Accounts receivable, net	97,145
	Other assets	2,068
		496,810
	Liabilities
	Accounts payable and accrued expenses	94,771
	Other liabilities	1,500
		96,271
	Net assets acquired	$	400,539
	Cash, net of amounts received for preferential rights	$	358,239
	Fair value of the Shares issued to MHR	42,300
	Consideration paid	$	400,539
Business Acquisition, Pro Forma Information [Table Text Block]	'
	The results of operations attributable to the EF Acquisition have been included in our Condensed Consolidated Financial Statements from the Acquisition Date. The following table presents unaudited summary pro forma financial information for the period presented assuming the EF Acquisition and the related financing occurred as of January 1, 2012. The pro forma financial information does not purport to represent what our results of operations would have been if the EF Acquisition had occurred as of this date or the results of operations for any future periods.
		Three Months
		Ended
		31-Mar-13
	Total revenues	$	109,064
	Net loss attributable to common shareholders	$	(15,204	)
	Loss per share - basic and diluted	$	(0.23	)

Accounts_Receivable_and_Major_1

Accounts Receivable and Major Customers (Tables)	3 Months Ended
	Mar. 31, 2014
Receivables [Abstract]	'
Summary of Accounts Receivable	'
	The following table summarizes our accounts receivable by type as of the dates presented:
		As of
		March 31,			December 31,
		2014			2013
	Customers	$	92,612		$	93,288
	Joint interest partners	43,860			76,199
	Other 1	31,340			25,538
		167,812			195,025
	Less: Allowance for doubtful accounts	(622		)	(622		)
		$	167,190		$	194,403

Derivative_Instruments_Tables

Derivative Instruments (Tables)	3 Months Ended
	Mar. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Commodity Derivative Positions	'
	The following table sets forth our commodity derivative positions as of March 31, 2014:
				Average
				Volume Per			Weighted Average Price								Fair Value
		Instrument		Day			Floor/Swap				Ceiling				Asset				Liability
	Crude Oil:			(barrels)			($/barrel)
	Second quarter 2014	Collars		2,500			$	92			$	99.46			$	—			$	740
	Third quarter 2014	Collars		2,000			$	90			94.33				—				827
	Fourth quarter 2014	Collars		2,000			$	90			94.33				—				420
	First quarter 2015	Collars		4,000			$	87.5			94.66				—				278
	Second quarter 2015	Collars		4,000			$	87.5			94.66				276				—
	Third quarter 2015	Collars		3,000			$	86.67			94.73				507				—
	Fourth quarter 2015	Collars		3,000			$	86.67			94.73				766				—
	Second quarter 2014	Swaps		8,500			$	94							—				4,984
	Third quarter 2014	Swaps		10,000			$	93.21							342				4,410
	Fourth quarter 2014	Swaps		10,000			$	93.21							709				2,417
	First quarter 2015	Swaps		7,000			$	90.79							—				1,440
	Second quarter 2015	Swaps		7,000			$	90.79							—				447
	Third quarter 2015	Swaps		6,000			$	90.45							150				—
	Fourth quarter 2015	Swaps		6,000			$	90.45							722				—
	First quarter 2015	Swaptions		1,000			$	88							—				535
	Second quarter 2015	Swaptions		1,000			$	88							—				534
	Third quarter 2015	Swaptions		1,000			$	88							—				534
	Fourth quarter 2015	Swaptions		1,000			$	88							—				534
	Natural Gas:			(in MMBtu)			($/MMBtu)
	Second quarter 2014	Swaps		15,000			$	4.1							—				474
	Third quarter 2014	Swaps		15,000			$	4.1							—				450
	Fourth quarter 2014	Swaps		5,000			$	4.5							—				2
	First quarter 2015	Swaps		5,000			$	4.5							—				49
	Settlements to be paid in subsequent period														—				1,761
Impact of Derivative Activities on Condensed Consolidated Statements of Income	'
	The impact of our derivatives activities on income is included in the Derivatives caption on our Condensed Consolidated Statements of Operations. The following table summarizes the effects of our derivative activities for the periods presented:
						Three Months Ended
						March 31,
						2014				2013
	Impact by contract type:
	Commodity contracts					$	(15,662	)		$	(7,761	)
	Interest rate contracts					—				—
						$	(15,662	)		$	(7,761	)
	Cash settlements and gains (losses):
	Cash (paid) received for:
	Commodity contract settlements					$	(3,057	)		$	3,557
	Interest rate contract settlements					—				—
						(3,057		)		3,557
	Losses attributable to:
	Commodity contracts					(12,605		)		(11,318		)
	Interest rate contracts					—				—
						(12,605		)		(11,318		)
						$	(15,662	)		$	(7,761	)
Fair Value of Derivative Instruments on Condensed Consolidated Balance Sheets	'
	The following table summarizes the fair values of our derivative instruments as well as the locations of these instruments, on our Condensed Consolidated Balance Sheets as of the dates presented:
					Fair Values as of
					31-Mar-14								31-Dec-13
					Derivative				Derivative				Derivative				Derivative
	Type		Balance Sheet Location		Assets				Liabilities				Assets				Liabilities
	Commodity contracts		Derivative assets/liabilities - current		$	65			$	19,403			$	3,830			$	10,141
	Interest rate contracts		Derivative assets/liabilities - current		—				—				—				—
					65				19,403				3,830				10,141
	Commodity contracts		Derivative assets/liabilities - noncurrent		1,974				—				1,552				—
	Interest rate contracts		Derivative assets/liabilities - noncurrent		—				—				—				—
					1,974				—				1,552				—
					$	2,039			$	19,403			$	5,382			$	10,141

Property_and_Equipment_Tables

Property and Equipment (Tables)	3 Months Ended
	Mar. 31, 2014
Property, Plant and Equipment [Abstract]	'
Summary of Property and Equipment	'
	The following table summarizes our property and equipment as of the dates presented:
		As of
		March 31,			December 31,
		2014			2013
	Oil and gas properties:
	Proved	$	462,404		$	460,255
	Unproved	101,426			101,520
	Total oil and gas properties	563,830			561,775
	Other property and equipment:
	Wells equipment and facilities	2,738,102			2,593,700
	Support equipment	21,857			21,513
	Total other property and equipment	2,759,959			2,615,213
		3,323,789			3,176,988
	Accumulated depreciation, depletion and amortization	(1,011,786		)	(939,684		)
		$	2,312,003		$	2,237,304

LongTerm_Debt_Tables

Long-Term Debt (Tables)	3 Months Ended
	Mar. 31, 2014
Debt Disclosure [Abstract]	'
Carrying Amount of Components of Long-term Debt	'
	The following table summarizes our long-term debt as of the dates presented:
		As of
		March 31,		December 31,
		2014		2013
	Revolving credit facility	$	190,000	$	206,000
	Senior notes due 2019	300,000		300,000
	Senior notes due 2020	775,000		775,000
		$	1,265,000	$	1,281,000

Additional_Balance_Sheet_Detai1

Additional Balance Sheet Detail (Tables)	3 Months Ended
	Mar. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Components of Selected Balance Sheet Accounts	'
	The following table summarizes components of selected balance sheet accounts as of the dates presented:
		As of
		March 31,		December 31,
		2014		2013
	Other current assets:
	Tubular inventory and well materials	$	1,965	$	2,271
	Prepaid expenses	3,407		3,653
		$	5,372	$	5,924
	Other assets:
	Debt issuance costs	$	29,227	$	30,239
	Assets of supplemental employee retirement plan (“SERP”)	3,815		3,734
	Other	668		562
		$	33,710	$	34,535
	Accounts payable and accrued liabilities:
	Trade accounts payable	$	75,235	$	120,278
	Drilling and other lease operating costs	62,620		51,529
	Royalties	41,860		39,929
	Production and franchise taxes	1,929		5,338
	Compensation - related	7,951		8,584
	Interest	37,833		15,718
	Preferred stock dividends	1,722		1,725
	Other	9,062		4,903
		$	238,212	$	248,004
	Other liabilities:
	Deferred gain on sale of assets	$	10,095	$	—
	Firm transportation obligation	12,964		13,245
	Asset retirement obligations (“AROs”)	6,537		6,437
	Defined benefit pension obligations	1,523		1,579
	Postretirement health care benefit obligations	1,071		1,023
	Deferred compensation - SERP obligations and other	4,089		3,883
	Other	8,766		7,219
		$	45,045	$	33,386

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Summary of Long-Term Debt with Fixed Interest Rates	'
	The following table summarizes the fair value of our long-term debt with fixed interest rates, which is estimated based on the published market prices for these debt obligations, as of the dates presented:
		As of
		31-Mar-14								31-Dec-13
		Fair				Carrying				Fair				Carrying
		Value				Value				Value				Value
	Senior Notes due 2019	$	318,000			$	300,000			$	307,500			$	300,000
	Senior Notes due 2020	862,188				775,000				837,969				775,000
		$	1,180,188			$	1,075,000			$	1,145,469			$	1,075,000
Assets and Liabilities Measured at Fair Value on Recurring Basis	'
	The following tables summarize the valuation of those assets and liabilities as of the dates presented:
			As of March 31, 2014
			Fair Value				Fair Value Measurement Classification
	Description		Measurement				Level 1				Level 2				Level 3
	Assets:
	Commodity derivative assets - current		$	65			$	—			$	65			$	—
	Commodity derivative assets - noncurrent		1,974				—				1,974				—
	Assets of SERP		3,815				3,815				—				—
	Liabilities:
	Commodity derivative liabilities - current		(19,403		)		—				(19,403		)		—
	Commodity derivative liabilities - noncurrent		—				—				—				—
	Deferred compensation - SERP obligations		(4,084		)		(4,084		)		—				—
			As of December 31, 2013
			Fair Value				Fair Value Measurement Classification
	Description		Measurement				Level 1				Level 2				Level 3
	Assets:
	Commodity derivative assets - current		$	3,830			$	—			$	3,830			$	—
	Commodity derivative assets - noncurrent		1,552				—				1,552				—
	Assets of SERP		3,734				3,734				—				—
	Liabilities:
	Commodity derivative liabilities - noncurrent		(10,141		)		—				(10,141		)		—
	Deferred compensation - SERP obligations		(3,879		)		(3,879		)		—				—

Shareholders_Equity_Tables

Shareholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2014
Equity [Abstract]	'
Schedule of Stockholders Equity [Table Text Block]	'
	The following tables summarize the components of our shareholders’ equity and the changes therein as of and for the three months ended March 31, 2014 and 2013:
		As of												As of
		December 31,						Dividends			All Other			March 31,
		2013			Net Loss			Declared 1			Changes 2			2014
	Preferred stock 3	$	1,150		$	—		$	—		$	(2	)	$	1,148
	Common stock 3	466			—			—			2			468
	Paid-in capital 3	891,351			—			—			1,911			893,262
	Retained earnings	(104,180		)	19,225			(1,722		)	—			(86,677		)
	Deferred compensation obligation	2,792			—			—			105			2,897
	Accumulated other comprehensive income 4	267			—			—			25			292
	Treasury stock	(3,042		)	—			—			(105		)	(3,147		)
		$	788,804		$	19,225		$	(1,722	)	$	1,936		$	808,243
		As of												As of
		December 31,						Dividends			All Other			March 31,
		2012			Net Loss			Declared 1			Changes 2			2013
	Preferred stock	$	1,150		$	—		$	—		$	—		$	1,150
	Common stock	364			—			—			1			365
	Paid-in capital	849,046			—			—			664			849,710
	Retained earnings	45,790			(16,383		)	(1,725		)	—			27,682
	Deferred compensation obligation	3,111			—			—			65			3,176
	Accumulated other comprehensive loss 4	(982		)	—			—			19			(963		)
	Treasury stock	(3,363		)	—			—			(64		)	(3,427		)
		$	895,116		$	(16,383	)	$	(1,725	)	$	685		$	877,693
	_______________________
	1 Includes dividends of $150.00 per share of 6% Convertible Perpetual Preferred Stock (the “6% Preferred Stock”).
	2 Includes equity-classified share-based compensation of $825 and $1,085 for the three months ended March 31, 2014 and 2013.
	3 A total of 19.5 shares, or 1,950 depositary shares, of 6% Preferred Stock were converted into 32,500 shares of our common stock during the three months ended March 31, 2014.
	4 The Accumulated other comprehensive income (loss) (“AOCI”) is entirely attributable to our defined benefit pension and postretirement health care plans. The changes in the balance of AOCI for the three months ended March 31, 2014 and 2013 represent reclassifications from AOCI to net periodic benefit expense, a component of General and administrative expenses, of $38 and $29 and are presented above net of taxes of $13 and $10.

ShareBased_Compensation_Tables

Share-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Summary of Share-Based Compensation Expense	'
	The following table summarizes our share-based compensation expense recognized for the periods presented:
		Three Months Ended
		March 31,
		2014		2013
	Equity-classified awards:
	Stock option awards	$	461	$	792
	Common, deferred and restricted stock and stock unit awards	364		293
		825		1,085
	Liability-classified awards	5,945		14
		$	6,770	$	1,099

Restructuring_and_Exit_Activit1

Restructuring and Exit Activities (Tables)	3 Months Ended
	Mar. 31, 2014
Restructuring and Related Activities [Abstract]	'
Summary of Restructuring Related Obligations	'
	The following table summarizes our restructuring and exit activity-related obligations and the changes therein for the periods presented:
		Three Months Ended
		March 31,
		2014			2013
	Balance at beginning of period	$	16,090		$	17,263
	Employee, office and other costs accrued, net	12			—
	Accretion of firm transportation obligation	354			207
	Cash payments, net	(650		)	(498		)
	Balance at end of period	$	15,806		$	16,972

Interest_Expense_Tables

Interest Expense (Tables)	3 Months Ended
	Mar. 31, 2014
Banking and Thrift [Abstract]	'
Interest Expense Net Disclosure	'
	The following table summarizes the components of interest expense for the periods presented:
		Three Months Ended
		March 31,
		2014			2013
	Interest on borrowings and related fees	$	23,140		$	13,583
	Accretion of original issue discount 1	—			321
	Amortization of debt issuance costs	1,012			626
	Capitalized interest 2	(1,618		)	(51		)
		$	22,534		$	14,479

Earnings_per_Share_Tables

Earnings per Share (Tables)	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Components of Calculation of Basic and Diluted Earnings Per Share	'
	The following table provides a reconciliation of the components used in the calculation of basic and diluted earnings per share for the periods presented:
		Three Months Ended
		March 31,
		2014			2013
	Net income (loss)	$	19,225		$	(16,383	)
	Less: Preferred stock dividends	(1,722		)	(1,725		)
	Net income (loss) attributable to common shareholders - Basic	17,503			(18,108		)
	Add: Preferred stock dividends	1,722			—
	Net income (loss) attributable to common shareholders - Diluted	$	19,225		$	(18,108	)
	Weighted-average shares - Basic	65,611			55,341
	Effect of dilutive securities 1	20,133			—
	Weighted-average shares - Diluted	85,744			55,341
	_______________________
	1 For the three months ended March 31, 2013, approximately 19.2 million potentially dilutive securities, including the 6% Preferred Stock, stock options and restricted stock units, had the effect of being anti-dilutive and were excluded from the calculation of diluted earnings per common share.

Acquisitions_and_Divestitures_

Acquisitions and Divestitures Purchase Price Allocation (Details) (USD $)	0 Months Ended	3 Months Ended	4 Months Ended
Share data in Millions, except Per Share data, unless otherwise specified	Apr. 24, 2013	Jun. 30, 2013	Apr. 24, 2013	Mar. 31, 2014	Dec. 31, 2013
Acquisitions and Divestitures [Abstract]	'	'	'	'	'
Business Acquisition, Total Consideration Transferred, Net of Proceeds From Investing Partners	$380,000,000	'	'	'	'
Business Acquisition, Purchase Price Adjustments, Effective Date to Date of Acquisition	'	'	19,000,000	'	'
Stock Issued During Period, Shares, Acquisitions	10	'	'	'	'
Stock Issued during period, Fair Value per Share, Acquisitions	$4.23	'	$4.23	'	'
Proceeds From Joint Interest Partners Upon Exercise of Preferential Rights Related to the Acquisition	'	21,000,000	'	'	'
BusinessAcquisition, Oil and Gas Properties - Proved	277,888,000	'	277,888,000	2,738,102,000	2,593,700,000
BusinessAcquisitionsPurchasePriceAllocationUnprovedOilandGasProperties	119,709,000	'	119,709,000	'	'
Business Acquisition, Purchase Price Allocation, Current Assets, Receivables	97,145,000	'	97,145,000	'	'
Business Acquisition, Purchase Price Allocation, Current Assets, Prepaid Expense and Other Assets	2,068,000	'	2,068,000	'	'
Business Acquisition, Purchase Price Allocation, Assets Acquired	496,810,000	'	496,810,000	'	'
Business Acquisition, Purchase Price Allocation, Current Liabilities, Accounts Payable	94,771,000	'	94,771,000	'	'
Business Acquisition, Purchase Price Allocation, Current Liabilities, Accrued Liabilities	1,500,000	'	1,500,000	'	'
Business Acquisition, Purchase Price Allocation, Liabilities Assumed	96,271,000	'	96,271,000	'	'
Business Acquisition, Purchase Price Allocation, Assets Acquired (Liabilities Assumed), Net	400,539,000	'	400,539,000	'	'
Cash Payments To Acquire Business, Net of Amounts Received for Preferential Rights	358,239,000	'	'	'	'
Stock Issued During Period, Value, Acquisitions	42,300,000	'	'	'	'
Business Combination, Consideration Transferred	$400,539,000	'	'	'	'

Acquisitions_and_Divestitures_1

Acquisitions and Divestitures Business Acquisition, Pro-Forma Information (Details) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2013
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]	'
Business Acquisition, Pro Forma Revenue	$109,064
Business Acquisition, Pro Forma Net Income (Loss)	($15,204)
Business Acquisition, Pro Forma Earnings Per Share, Basic	($0.23)

Acquisitions_and_Divestitures_2

Acquisitions and Divestitures - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Jan. 31, 2014
Business Acquisition [Line Items]	'	'	'
Business Combination, Undisputed Contractual Adjustments, in Arbitration	'	$26.50	'
Proceeds from sale of legacy natural gas assets in West Virginia, Kentucky and Virginia	96	'	'
Gain (Loss) on Sale of Oil and Gas Property	67.3	'	'
Sale Leaseback Transaction, Recognized Gain, Net	56.7	'	'
Sale Leaseback Transaction, Deferred Gain, Gross	'	'	10.6
Sale Leaseback Transaction, Current Period Gain Recognized	0.1	'	'
Sale Leaseback Transaction, Deferred Gain, Current	0.4	'	'
Sale Leaseback Transaction, Deferred Gain, Net	$10.10	'	'

Summary_of_Accounts_Receivable

Summary of Accounts Receivable (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Receivables [Abstract]	'	'
Customers	$92,612	$93,288
Joint interest partners	43,860	76,199
Other 1	31,340	25,538
Accounts Receivable, Gross, Current, Total	167,812	195,025
Less: Allowance for doubtful accounts	-622	-622
Accounts receivable, net of allowance for doubtful accounts	$167,190	$194,403

Accounts_Receivable_and_Major_2

Accounts Receivable and Major Customers - Additional Information (Detail) (USD $)

3 Months Ended

12 Months Ended

In Millions, unless otherwise specified

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Dec. 31, 2012

Dec. 31, 2013

Sales Revenue

Sales Revenue

Sales Revenue

Sales Revenue

Sales Revenue

Sales Revenue

Sales Revenue

Sales Revenue

Sales Revenue

Sales Revenue

Accounts Receivable

Accounts Receivable

Accounts Receivable

Customer Concentration Risk

Customer Concentration Risk

Customer Concentration Risk

Customer Concentration Risk

Customer Concentration Risk

Customer Concentration Risk

Customer Concentration Risk

Customer Concentration Risk

Customer Concentration Risk

Customer Concentration Risk

Credit Concentration Risk

Credit Concentration Risk

Credit Concentration Risk

Customer

Customer

Major Customer 1

Major Customer 1

Major Customer 2

Major Customer 2

Major Customer 3

Major Customer 3

Major Customer 4

Major Customer 4

Accounts, Notes, Loans and Financing Receivable [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

Number of major customers

4

4

'

'

'

'

'

'

'

'

'

'

'

Revenues, major customers

$89.50

$46.20

$38.80

$16.10

$17.40

$10.90

$17.20

$10.60

$16.10

$8.60

'

'

'

Concentration risk, percentage

67.00%

56.00%

29.00%

20.00%

13.00%

13.00%

13.00%

13.00%

12.00%

10.00%

43.00%

40.00%

'

Accounts receivable, major customers

'

'

'

'

'

'

'

'

'

'

$40

'

$36.90

Derivative_Instruments_Additio

Derivative Instruments - Additional Information (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014
In Thousands, unless otherwise specified			7.25% Senior Unsecured Notes due 2019	Commodity contracts	Commodity contracts	Commodity contracts	Commodity contracts
				Entity	Credit Concentration Risk	Natural Gas	Crude Oil
					Entity
Derivative Instruments and Hedging Activities Disclosure [Line Items]	'	'	'	'	'	'	'
Third-party quoted forward prices	'	'	'	'	'	'NYMEX Henry Hub gas	'West Texas Intermediate crude oil
Annual interest rate	'	'	7.25%	'	'	'	'
Derivative assets	$2,039	$5,382	'	$2,000	'	'	'
Number of derivative counterparty	'	'	'	5	3	'	'

Commodity_Derivative_Positions

Commodity Derivative Positions (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014
	bbl
Settlements to be paid in subsequent period	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Fair Value Asset	$0
Fair Value Liability	1,761
Crude Oil | Group One	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Term	30-Sep-14
Instrument	'Collars
Derivative, Nonmonetary Notional Amount	2,000
Weighted Average Price, Floor/Swap	90
Weighted Average Price, Ceiling	94,330
Fair Value Asset	0
Fair Value Liability	827
Crude Oil | Group Four [Member]	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Term	31-Dec-14
Instrument	'Collars
Derivative, Nonmonetary Notional Amount	2,000
Weighted Average Price, Floor/Swap	90
Weighted Average Price, Ceiling	94,330
Fair Value Asset	0
Fair Value Liability	420
Crude Oil | Group Five [Member]	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Term	31-Mar-15
Instrument	'Collars
Derivative, Nonmonetary Notional Amount	4,000
Weighted Average Price, Floor/Swap	87.5
Weighted Average Price, Ceiling	94,660
Fair Value Asset	0
Fair Value Liability	278
Crude Oil | Group Six [Member]	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Term	30-Jun-15
Instrument	'Collars
Derivative, Nonmonetary Notional Amount	4,000
Weighted Average Price, Floor/Swap	87.5
Weighted Average Price, Ceiling	94,660
Fair Value Asset	276
Fair Value Liability	0
Crude Oil | Group Eight [Member]	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Instrument	'Collars
Derivative, Nonmonetary Notional Amount	3,000
Weighted Average Price, Floor/Swap	86.67
Weighted Average Price, Ceiling	94,730
Fair Value Asset	507
Fair Value Liability	0
Crude Oil | Group Two	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Term	30-Jun-14
Instrument	'Collars
Derivative, Nonmonetary Notional Amount	2,500
Weighted Average Price, Floor/Swap	92
Weighted Average Price, Ceiling	99.46
Fair Value Asset	0
Fair Value Liability	740
Crude Oil | Group Six	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Term	31-Dec-15
Instrument	'Collars
Derivative, Nonmonetary Notional Amount	3,000
Weighted Average Price, Floor/Swap	86.67
Weighted Average Price, Ceiling	94,730
Fair Value Asset	766
Fair Value Liability	0
Crude Oil | Group Seven	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Term	31-Mar-15
Instrument	'Swaps
Derivative, Nonmonetary Notional Amount	7,000
Derivative, Swap Type, Average Fixed Price	90.79
Fair Value Asset	0
Fair Value Liability	1,440
Crude Oil | Group Eight	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Term	30-Jun-14
Instrument	'Swaps
Derivative, Nonmonetary Notional Amount	8,500
Derivative, Swap Type, Average Fixed Price	94
Fair Value Asset	0
Fair Value Liability	4,984
Crude Oil | Group Nine	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Term	30-Sep-14
Instrument	'Swaps
Derivative, Nonmonetary Notional Amount	10,000
Derivative, Swap Type, Average Fixed Price	93.21
Fair Value Asset	342
Fair Value Liability	4,410
Crude Oil | Group Fourteen	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Term	31-Dec-14
Instrument	'Swaps
Derivative, Nonmonetary Notional Amount	10,000
Derivative, Swap Type, Average Fixed Price	93.21
Fair Value Asset	709
Fair Value Liability	2,417
Crude Oil | Group Ten	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Term	31-Mar-15
Instrument	'Swaptions
Derivative, Nonmonetary Notional Amount	1,000
Derivative, Average Price Risk Option Strike Price	88
Fair Value Asset	0
Fair Value Liability	535
Crude Oil | Group Eleven	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Term	30-Jun-15
Instrument	'Swaptions
Derivative, Nonmonetary Notional Amount	1,000
Derivative, Average Price Risk Option Strike Price	88
Fair Value Asset	0
Fair Value Liability	534
Crude Oil | Group Fifteen	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Term	30-Sep-15
Instrument	'Swaptions
Derivative, Nonmonetary Notional Amount	1,000
Derivative, Average Price Risk Option Strike Price	88
Fair Value Asset	0
Fair Value Liability	534
Crude Oil | Group Sixteen	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Term	31-Dec-15
Instrument	'Swaptions
Derivative, Nonmonetary Notional Amount	1,000
Derivative, Average Price Risk Option Strike Price	88
Fair Value Asset	0
Fair Value Liability	534
Crude Oil | Group Nineteen	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Term	30-Jun-15
Instrument	'Swaps
Derivative, Nonmonetary Notional Amount	7,000
Derivative, Swap Type, Average Fixed Price	90.79
Fair Value Asset	0
Fair Value Liability	447
Crude Oil | Group Twenty Four	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Term	30-Sep-15
Instrument	'Swaps
Derivative, Nonmonetary Notional Amount	6,000
Derivative, Swap Type, Average Fixed Price	90.45
Fair Value Asset	150
Fair Value Liability	0
Crude Oil | Group Thirty-Two	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Term	31-Dec-15
Instrument	'Swaps
Derivative, Nonmonetary Notional Amount	6,000
Derivative, Swap Type, Average Fixed Price	90.45
Fair Value Asset	722
Fair Value Liability	0
Natural Gas | Group Three	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Term	31-Dec-14
Instrument	'Swaps
Average Volume Per Day (MMBtu)	5,000
Weighted Average Price, Floor/Swap	4.5
Fair Value Asset	0
Fair Value Liability	2
Natural Gas | Group Twenty-Seven	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Term	30-Jun-13
Instrument	'Swaps
Average Volume Per Day (MMBtu)	15,000
Weighted Average Price, Floor/Swap	4.1
Fair Value Asset	0
Fair Value Liability	474
Natural Gas | Group Twenty-Eight	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Term	30-Sep-14
Instrument	'Swaps
Average Volume Per Day (MMBtu)	15,000
Weighted Average Price, Floor/Swap	4.1
Fair Value Asset	0
Fair Value Liability	450
Natural Gas | Group Thirty-One	'
Derivative Instruments Related to Oil and Gas Production [Line Items]	'
Term	31-Mar-15
Instrument	'Swaps
Average Volume Per Day (MMBtu)	5,000
Weighted Average Price, Floor/Swap	4.5
Fair Value Asset	0
Fair Value Liability	$49

Impact_of_Derivative_Activitie

Impact of Derivative Activities on Condensed Consolidated Statements of Income (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Derivatives	($15,662)	($7,761)
Cash received	-3,057	3,557
Unrealized gains (losses)	-12,605	-11,318
Commodity contracts	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Derivatives	-15,662	-7,761
Cash received	3,057	-3,557
Unrealized gains (losses)	-12,605	-11,318
Interest rate contracts	'	'
Derivative Instruments, Gain (Loss) [Line Items]	'	'
Derivatives	0	0
Cash received	0	0
Unrealized gains (losses)	$0	$0

Fair_Value_of_Derivative_Instr

Fair Value of Derivative Instruments on Condensed Consolidated Balance Sheets (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Derivatives, Fair Value [Line Items]	'	'
Derivative assets, current	$65	$3,830
Derivative assets, noncurrent	1,974	1,552
Derivative assets	2,039	5,382
Derivative liabilities, current	19,403	10,141
Derivative liabilities, noncurrent	0	0
Derivative liabilities	19,403	10,141
Commodity contracts	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative assets	2,000	'
Commodity contracts | Derivative assets/liabilities - current	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative assets, current	65	3,830
Derivative liabilities, current	19,403	10,141
Commodity contracts | Derivative assets/liabilities - noncurrent	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative assets, noncurrent	1,974	1,552
Derivative liabilities, noncurrent	0	0
Interest rate contracts | Derivative assets/liabilities - current	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative assets, current	0	0
Derivative liabilities, current	0	0
Interest rate contracts | Derivative assets/liabilities - noncurrent	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative assets, noncurrent	0	0
Derivative liabilities, noncurrent	$0	$0

Summary_of_Property_and_Equipm

Summary of Property and Equipment (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Apr. 24, 2013
In Thousands, unless otherwise specified
Oil and gas properties:	'	'	'
Proved	$462,404	$460,255	'
Unproved	101,426	101,520	'
Total oil and gas properties	563,830	561,775	'
Capitalized Costs, Proved Properties	2,738,102	2,593,700	277,888
Support equipment	2,759,959	2,615,213	'
Total other property and equipment	3,323,789	3,176,988	'
Accumulated depreciation, depletion and amortization	-1,011,786	-939,684	'
Property and equipment, net (successful efforts method)	2,312,003	2,237,304	'
Support Equipment and Facilities [Member]	'	'	'
Oil and gas properties:	'	'	'
Support equipment	$21,857	$21,513	'

Summary_of_LongTerm_Debt_Detai

Summary of Long-Term Debt (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'	'
Revolving credit facility	$190,000	$206,000
Total	1,265,000	1,281,000
7.25% Senior Unsecured Notes due 2019	'	'
Debt Instrument [Line Items]	'	'
Senior notes	300,000	300,000
8.5% Senior Notes due 2020	'	'
Debt Instrument [Line Items]	'	'
Senior notes	$775,000	$775,000

LongTerm_Debt_Additional_Infor

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

3 Months Ended

12 Months Ended

3 Months Ended

3 Months Ended

Mar. 31, 2014

Mar. 31, 2014

Dec. 31, 2012

Oct. 28, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Oct. 28, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Dec. 31, 2013

9-May-14

Revolving credit facility

Revolving credit facility

Revolving credit facility

Revolving credit facility

Revolving credit facility

Revolving credit facility

Revolving credit facility

Revolving credit facility

Revolving credit facility

Revolving credit facility

Revolving credit facility

Previous Revolving Credit Facility

Previous Revolving Credit Facility

7.25% Senior Unsecured Notes due 2019

7.25% Senior Unsecured Notes due 2019

7.25% Senior Unsecured Notes due 2019

7.25% Senior Unsecured Notes due 2019

Senior Notes due 2020 [Member]

Senior Notes due 2020 [Member]

Subsequent Event [Member]

Minimum

Maximum

through December 31, 2013

through June 30, 2014

through maturity

Group Twelve

Group Thirteen

Letter of Credit

Group One

Group Two

Previous Revolving Credit Facility

Maximum

Maximum

Maximum

Debt Disclosure [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Senior Notes, Noncurrent

'

'

'

'

'

'

'

'

'

'

'

'

'

'

$300,000,000

$300,000,000

'

'

$775,000,000

$775,000,000

'

Line Of Credit Facility Borrowing Base

'

'

'

'

'

'

'

'

'

'

'

'

'

425,000,000

'

'

'

'

'

'

475,000,000

Maximum borrowing capacity

'

'

'

400,000,000

'

'

'

'

'

'

'

20,000,000

'

'

'

'

'

'

'

'

'

Optional additional borrowing

'

200,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Letter of credit amount outstanding

'

'

'

'

'

'

'

'

'

'

'

'

1,700,000

'

'

'

'

'

'

'

'

Available borrowing capacity

'

'

'

'

'

'

'

'

'

'

'

'

$208,300,000

'

'

'

'

'

'

'

'

Credit facility interest rate description

'

'

'Borrowings under the Revolver bear interest, at our option, at either (i) a rate derived from the London Interbank Offered Rate, as adjusted for statutory reserve requirements for Eurocurrency liabilities (the “Adjusted LIBOR”), plus an applicable margin ranging from 1.500% to 2.500% or (ii) the greater of (a) the prime rate, (b) the federal funds effective rate plus 0.5% or (c) the one-month Adjusted LIBOR plus 1.0%, and, in each case, plus an applicable margin (ranging from 0.500% to 1.500%). The applicable margin is determined based on the ratio of our outstanding borrowings to the available Revolver capacity.

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Credit facility interest rate option one, applicable margin rate over Adjusted LIBOR

'

'

'

'

1.50%

2.50%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Credit facility interest rate option two, base rate over federal funds effective rate

'

0.50%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Description of Variable Rate Basis

'one-month Adjusted LIBOR

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Credit facility interest rate option two, base rate over one-month Adjusted LIBOR

'

1.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Credit facility interest rate option two, applicable margin rate

'

1.75%

'

'

0.50%

1.50%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Commitment fees for undrawn credit facility

'

'

'

'

'

'

'

'

'

0.38%

0.50%

'

'

'

'

'

'

'

'

'

'

LIne of Credit Facility, Commitment Fee Percentage at Period End

'

0.38%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of Credit Facility, Interest Rate at Period End

'

1.94%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of Credit Facility, Interest Rate at Period End, LIBOR component

'

0.19%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Current ratio

'

'

'

'

1

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt to EBITDAX ratio

'

'

'

'

'

'

4.5

4.25

4

'

'

'

'

'

'

'

'

'

'

'

'

Annual interest rate

'

'

'

'

'

'

'

'

'

'

'

'

'

'

7.25%

'

'

'

'

'

'

Redemption option, percent of principal

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

103.63%

100.00%

'

'

'

Income_Taxes_Details

Income Taxes (Details)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Tax Disclosure [Abstract]	'	'
Effective Income Tax Rate Reconciliation, Percent	42.60%	34.90%

Components_of_Selected_Balance

Components of Selected Balance Sheet Accounts (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Other current assets:	'	'
Tubular inventory and well materials	$1,965	$2,271
Prepaid expenses	3,407	3,653
Prepaid Expense and Other Assets, Current, Total	5,372	5,924
Other assets:	'	'
Debt issuance costs	29,227	30,239
Assets of supplemental employee retirement plan (“SERP”)	3,815	3,734
Other	668	562
Other assets	33,710	34,535
Accounts payable and accrued liabilities:	'	'
Trade accounts payable	75,235	120,278
Drilling and other lease operating costs	62,620	51,529
Royalties	41,860	39,929
Production and franchise taxes	1,929	5,338
Compensation - related	7,951	8,584
Interest	37,833	15,718
Preferred stock dividends	1,722	1,725
Other	9,062	4,903
Accounts payable and accrued liabilities	238,212	248,004
Other liabilities:	'	'
Sale Leaseback Transaction Deferred Gain Noncurrent	10,095	0
Firm transportation obligation	12,964	13,245
Asset retirement obligations (“AROs”)	6,537	6,437
Defined benefit pension obligations	1,523	1,579
Postretirement health care benefit obligations	1,071	1,023
Deferred compensation - SERP obligations and other	4,089	3,883
Other	8,766	7,219
Other liabilities	$45,045	$33,386

Fair_Value_Summary_of_LongTerm

Fair Value Summary of Long-Term Debt with Fixed Interest Rates (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term debt with fixed interest rates	$1,180,188	$1,145,469
Fair Value | 7.25% Senior Unsecured Notes due 2019	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term debt with fixed interest rates	318,000	307,500
Fair Value | Senior Notes due 2020 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term debt with fixed interest rates	862,188	837,969
Carrying Value	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term debt with fixed interest rates	1,075,000	1,075,000
Carrying Value | 7.25% Senior Unsecured Notes due 2019	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term debt with fixed interest rates	300,000	300,000
Carrying Value | Senior Notes due 2020 [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-term debt with fixed interest rates	$775,000	$775,000

Assets_and_Liabilities_Measure

Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Assets:	'	'
Commodity derivative assets - current	$65	$3,830
Commodity derivative assets - noncurrent	1,974	1,552
Liabilities:	'	'
Commodity derivative liabilities - current	-19,403	-10,141
Commodity derivative liabilities - noncurrent	0	0
Fair Value, Measurements, Recurring | Estimate of Fair Value, Fair Value Disclosure [Member]	'	'
Assets:	'	'
Assets of SERP	3,815	3,734
Liabilities:	'	'
Deferred compensation - SERP obligations	-4,084	-3,879
Fair Value, Measurements, Recurring | Level 1	'	'
Assets:	'	'
Assets of SERP	3,815	3,734
Liabilities:	'	'
Deferred compensation - SERP obligations	-4,084	-3,879
Fair Value, Measurements, Recurring | Level 2	'	'
Assets:	'	'
Assets of SERP	0	0
Liabilities:	'	'
Deferred compensation - SERP obligations	0	0
Fair Value, Measurements, Recurring | Level 3	'	'
Assets:	'	'
Assets of SERP	0	0
Liabilities:	'	'
Deferred compensation - SERP obligations	0	0
Fair Value, Measurements, Recurring | Commodity contracts | Estimate of Fair Value, Fair Value Disclosure [Member]	'	'
Assets:	'	'
Commodity derivative assets - current	65	3,830
Commodity derivative assets - noncurrent	1,974	1,552
Liabilities:	'	'
Commodity derivative liabilities - current	-19,403	'
Commodity derivative liabilities - noncurrent	0	-10,141
Fair Value, Measurements, Recurring | Commodity contracts | Level 1	'	'
Assets:	'	'
Commodity derivative assets - current	0	0
Commodity derivative assets - noncurrent	0	0
Liabilities:	'	'
Commodity derivative liabilities - current	0	'
Commodity derivative liabilities - noncurrent	0	0
Fair Value, Measurements, Recurring | Commodity contracts | Level 2	'	'
Assets:	'	'
Commodity derivative assets - current	65	3,830
Commodity derivative assets - noncurrent	1,974	1,552
Liabilities:	'	'
Commodity derivative liabilities - current	-19,403	'
Commodity derivative liabilities - noncurrent	0	-10,141
Fair Value, Measurements, Recurring | Commodity contracts | Level 3	'	'
Assets:	'	'
Commodity derivative assets - current	0	0
Commodity derivative assets - noncurrent	0	0
Liabilities:	'	'
Commodity derivative liabilities - current	0	'
Commodity derivative liabilities - noncurrent	$0	$0

Commitments_and_Contingencies_

Commitments and Contingencies - Additional Information (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2010	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014	Mar. 31, 2014
In Millions, unless otherwise specified		Legal Reserve	Contract Drilling	Maximum	Maximum	Minimum [Member]	Gas Gathering And Compression Services [Member]
				Contract Drilling	Firm Transportation [Member]	Firm Transportation [Member]
Commitments and Contingencies Disclosure [Line Items]	'	'	'	'	'	'	'
Contract term	'	'	'	'14 months	'15 years	'1 year	'
Contract termination claims description	'	'	'early termination provisions that would require us to pay penalties if we terminate the agreements prior to the end of their original terms.	'	'	'	'
Loss on contract termination for default	'	'	$17.30	'	'	'	'
Contractual Obligation, Due in Next Twelve Months	'	'	'	'	'	'	3.7
Contractual Obligation, Due in Second Year	'	'	'	'	'	'	4.2
Contractual Obligation, Due in Third Year	'	'	'	'	'	'	5
Reserve established for contingency matters	'	0.9	'	'	'	'	'
Suspense account	1.8	'	'	'	'	'	'
Asset retirement obligations	$6.50	'	'	'	'	'	'

Shareholders_Equity_Rollforwar

Shareholders' Equity Rollforward (Details) (USD $)

3 Months Ended

3 Months Ended

In Thousands, except Share data, unless otherwise specified

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2013

Dec. 31, 2012

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Preferred stock 3

Preferred stock 3

Preferred stock 3

Preferred stock 3

Convertible Preferred Stock

Common stock 3

Common stock 3

Paid-in capital 3

Paid-in capital 3

Retained earnings

Retained earnings

Deferred compensation obligation

Deferred compensation obligation

Accumulated other comprehensive income 4

Accumulated other comprehensive income 4

Treasury stock

Treasury stock

Depositary Shares [Member]

Schedule of Stockholders' Equity [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Share-based Compensation

$825

$1,085

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Conversion of Stock, Shares Converted

'

'

'

'

'

'

19.5

'

'

'

'

'

'

'

'

'

'

'

'

1,950

Stock Issued During Period, Shares, Conversion of Convertible Securities

32,500

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Increase (Decrease) in Stockholders' Equity [Roll Forward]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

As of beginning balance

788,804

895,116

1,148

[1]

1,150

[1]

1,150

1,150

'

466

[1]

364

891,351

[1]

849,046

-104,180

45,790

2,792

3,111

267

[2]

-982

[2]

-3,042

-3,363

'

Net income (loss)

19,225

-16,383

'

'

'

'

'

'

'

'

'

19,225

-16,383

'

'

'

'

'

'

'

Dividends Declared

-1,722

[3]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Dividends Declared

'

-1,725

[1]

'

'

'

'

'

'

'

'

'

'

-1,725

[1]

'

'

'

'

'

'

'

All Other Changes

1,936

[4]

685

[4]

'

'

'

'

-2

[1],[4]

2

[1],[4]

1

[4]

1,911

[1],[4]

664

[4]

'

'

105

[4]

65

[4]

25

[2],[4]

19

[2],[4]

-105

[4]

-64

[4]

'

As of ending balance

808,243

877,693

1,148

[1]

1,150

[1]

1,150

1,150

'

468

[1]

365

893,262

[1]

849,710

-86,677

27,682

2,897

3,176

292

[2]

-963

[2]

-3,147

-3,427

'

Preferred stock dividends

($1,722)

($1,725)

'

'

'

'

'

'

'

'

'

($1,722)

[3]

'

'

'

'

'

'

'

'

[1]

3 A total of 19.5 shares, or 1,950 depositary shares, of 6% Preferred Stock were converted into 32,500 shares of our common stock during the three months ended March 31, 2014.

[2]

The Accumulated other comprehensive income (loss) (“AOCI”) is entirely attributable to our defined benefit pension and postretirement health care plans. The changes in the balance of AOCI for the three months ended March 31, 2014 and 2013 represent reclassifications from AOCI to net periodic benefit expense, a component of General and administrative expenses, of $38 and $29 and are presented above net of taxes of $13 and $10.

[3]

Includes dividends of $150.00 per share of 6% Convertible Perpetual Preferred Stock (the “6% Preferred Stock”).

[4]

Includes equity-classified share-based compensation of $825 and $1,085 for the three months ended March 31, 2014 and 2013.

Shareholders_Equity_Additional

Shareholders' Equity - Additional Information (Detail) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Class of Stock [Line Items]	'	'
Preferred stock dividends (in dollars per share)	$150	'
Preferred stock dividend rate	6.00%	6.00%
Other Comprehensive loss, pension and postretirements obligations, before tax	$38	$29
Change in pension and postretirement obligations, net of tax	$13	$10
Depositary Shares [Member]	'	'
Class of Stock [Line Items]	'	'
Conversion of Stock, Shares Converted	1,950	'

Summary_of_ShareBased_Compensa

Summary of Share-Based Compensation Expense (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'
Stock option awards	$461	$792
Common, deferred, restricted and restricted unit awards	364	293
Share-based compensation	825	1,085
Allocated Share-based Compensation Expense	6,770	1,099
Equity-classified awards:	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'
Share-based compensation	825	1,085
Liability-classified awards	'	'
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]	'	'
Share-based compensation	$5,945	$14

Restructuring_and_Exit_Activit2

Restructuring and Exit Activities - Additional Information (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
Restructuring Cost and Reserve [Line Items]	'	'
Restructuring reserve, noncurrent	$12,964,000	$13,245,000
Accounts Payable and Accrued Liabilities	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Restructuring reserve, current	2,700,000	'
Other Noncurrent Liabilities	'	'
Restructuring Cost and Reserve [Line Items]	'	'
Restructuring reserve, noncurrent	$13,100,000	'

Summary_of_Restructuring_Relat

Summary of Restructuring Related Obligations (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Sep. 30, 2012	Dec. 31, 2011
Restructuring Reserve [Roll Forward]	'	'	'	'
Balance at beginning of period	$16,090	'	$16,972	$17,263
Employee, office and other costs accrued, net	12	0	'	'
Accretion of firm transportation obligation	354	207	'	'
Cash payments, net	-650	-498	'	'
Balance at end of period	$15,806	'	$16,972	$17,263

Components_of_Interest_Expense

Components of Interest Expense (Detail) (USD $)	3 Months Ended
In Thousands, except Share data in Millions, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Banking and Thrift [Abstract]	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	'	19.2
Interest on borrowings and related fees	$23,140	$13,583
Accretion of original issue discount 1	0	321
Amortization of debt issuance costs	1,012	626
Capitalized interest 2	-1,618	-51
Interest expense	$22,534	$14,479

Components_of_Calculation_of_B

Components of Calculation of Basic and Diluted Earnings Per Share (Detail) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Earnings Per Share [Abstract]	'		'
Net income (loss)	$19,225		($16,383)
Less: Preferred stock dividends	-1,722		-1,725
Dilutive Securities, Effect on Basic Earnings Per Share, Dilutive Convertible Securities	1,722		0
Loss attributable to common shareholders - Basic and Diluted	17,503		-18,108
Net Income (Loss) Available to Common Stockholders, Diluted	$19,225		($18,108)
Weighted-average shares - Basic	65,611,000		55,341,000
Effect of dilutive securities	20,133,000	[1]	0	[1]
Weighted-average shares - Diluted	85,744,000		55,341,000
Preferred stock dividend rate	6.00%		6.00%
Potentially dilutive securities with the effect of being anti-dilutive excluded from the calculation of diluted earnings per common share (less than 0.1 million for the 3 months ended March 31, 2012)	'		19,200,000
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