Coterra Energy (CTRA) 10-Q 24 Apr 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015	Apr. 20, 2015
Document and Entity Information
Entity Registrant Name	CABOT OIL & GAS CORP
Entity Central Index Key	858470
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		413,603,811
Entity Current Reporting Status	Yes

CONDENSED_CONSOLIDATED_BALANCE

CONDENSED CONSOLIDATED BALANCE SHEET (Unaudited) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Current assets
Cash and cash equivalents	$13,948	$20,954
Accounts receivable, net	185,281	239,009
Inventories	14,087	14,026
Derivative instruments	134,041	137,603
Other current assets	2,046	1,855
Total current assets	349,403	413,447
Properties and equipment, net (Successful efforts method)	5,058,804	4,925,711
Equity method investments	74,528	68,029
Other assets	29,588	30,529
TOTAL ASSETS	5,512,323	5,437,716
Current liabilities
Accounts payable	321,215	400,076
Accrued liabilities	34,579	63,669
Income taxes payable	7,808	0
Deferred income taxes	39,144	35,273
Total current liabilities	402,746	499,018
Postretirement benefits	36,448	35,827
Long-term debt	1,877,000	1,752,000
Deferred income taxes	851,649	843,876
Asset retirement obligations	130,541	124,655
Other liabilities	38,408	39,607
Total liabilities	3,336,792	3,294,983
Commitments and contingencies
Stockholders' equity
Common stock: Authorized -- 960,000,000 shares of $0.10 par value in 2015 and 2014, respectively Issued-- 423,496,205 shares and 422,915,258 shares in 2015 and 2014, respectively	42,350	42,292
Additional paid-in capital	711,180	710,432
Retained earnings	1,730,987	1,698,995
Accumulated other comprehensive income (loss)	-2,151	-2,151
Less treasury stock, at cost: 9,892,680 shares in 2015 and 2014, respectively	-306,835	-306,835
Total stockholders' equity	2,175,531	2,142,733
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$5,512,323	$5,437,716

CONDENSED_CONSOLIDATED_BALANCE1

CONDENSED CONSOLIDATED BALANCE SHEET (Unaudited) (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Common stock, authorized shares	960,000,000	960,000,000
Common stock, par value (in dollars per share)	$0.10	$0.10
Common stock, Issued shares	423,496,205	422,915,258
Treasury stock, shares	9,892,680	9,892,680

CONDENSED_CONSOLIDATED_STATEME

CONDENSED CONSOLIDATED STATEMENT OF OPERATIONS (Unaudited) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
OPERATING REVENUES
Natural gas	$360,191	$432,809
Crude oil and condensate	62,558	59,144
Gain (loss) on derivative instruments	34,123	0
Brokered natural gas	4,827	13,153
Other	3,066	4,697
TOTAL OPERATING REVENUES	464,765	509,803
OPERATING EXPENSES
Direct operations	36,017	35,834
Transportation and gathering	121,235	77,765
Brokered natural gas	3,739	11,860
Taxes other than income	11,280	13,044
Exploration	8,732	6,474
Depreciation, depletion and amortization	175,497	147,418
General and administrative	22,529	21,636
TOTAL OPERATING EXPENSES	379,029	314,031
Earnings (loss) on equity method investments	1,421	0
Gain (loss) on sale of assets	138	-1,285
INCOME FROM OPERATIONS	87,295	194,487
Interest expense	23,566	16,557
Income before income taxes	63,729	177,930
Income tax expense	23,474	70,899
NET INCOME	$40,255	$107,031
Earnings per share
Basic (in dollars per share)	$0.10	$0.26
Diluted (in dollars per share)	$0.10	$0.26
Weighted-average common shares outstanding
Basic (in shares)	413,344	416,900
Diluted (in shares)	414,771	418,513
Dividends per common share (in dollars per share)	$0.02	$0.02

CONDENSED_CONSOLIDATED_STATEME1

CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$40,255	$107,031
Other comprehensive income (loss), net of taxes:
Reclassification adjustment for settled cash flow hedge contracts	0	42,565	[1]
Changes in fair value of cash flow hedge contracts	0	-80,175	[2]
Total other comprehensive income (loss)	0	-37,610
Comprehensive income (loss)	$40,255	$69,421
[1]	Net of income taxes of $(28,210) for the three months ended MarchB 31, 2014.
[2]	Net of income taxes of $53,135 for the three months ended MarchB 31, 2014.

CONDENSED_CONSOLIDATED_STATEME2

CONDENSED CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME (Unaudited) (Parenthetical) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Reclassification adjustment for settled cash flow hedge contracts, income taxes	($28,210)
Changes in fair value of cash flow hedge contracts, income taxes	$53,135

CONDENSED_CONSOLIDATED_STATEME3

CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS (Unaudited) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$40,255	$107,031
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation, depletion and amortization	175,497	147,418
Deferred income tax expense	15,081	57,603
(Gain) loss on sale of assets	-138	1,285
Exploration expense	162	2,040
(Gain) loss on derivative instruments	3,562	0
Amortization of debt issuance costs	1,267	1,126
Stock-based compensation and other	4,490	3,029
Changes in assets and liabilities:
Accounts receivable, net	49,615	-23,418
Income taxes	8,979	-16,889
Inventories	-61	7,076
Other current assets	-192	1,170
Accounts payable and accrued liabilities	-29,629	-16,089
Other assets and liabilities	1,930	39
Stock-based compensation tax benefit	-3,437	-16,043
Net cash provided by operating activities	267,381	255,378
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	-395,242	-338,701
Proceeds from sale of assets	3,081	108
Restricted cash	0	8,382
Investment in equity method investments	-5,078	-5,937
Net cash used in investing activities	-397,239	-336,148
CASH FLOWS FROM FINANCING ACTIVITIES
Borrowings from debt	382,000	366,000
Repayments of debt	-257,000	-291,000
Dividends paid	-8,263	-8,332
Stock-based compensation tax benefit	3,437	16,043
Other	2,678	90
Net cash provided by financing activities	122,852	82,801
Net (decrease) increase in cash and cash equivalents	-7,006	2,031
Cash and cash equivalents, beginning of period	20,954	23,400
Cash and cash equivalents, end of period	$13,948	$25,431

Financial_Statement_Presentati

Financial Statement Presentation	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Financial Statement Presentation	Financial Statement Presentation
	During interim periods, Cabot Oil & Gas Corporation (the Company) follows the same accounting policies disclosed in its Annual Report on Form 10-K for the year ended December 31, 2014 (Form 10-K) filed with the Securities and Exchange Commission (SEC). The interim financial statements should be read in conjunction with the notes to the consolidated financial statements and information presented in the Form 10-K. In management’s opinion, the accompanying interim condensed consolidated financial statements contain all material adjustments, consisting only of normal recurring adjustments, necessary for a fair statement. The results for any interim period are not necessarily indicative of the expected results for the entire year.
	Certain reclassifications have been made to prior year statements to conform with the current year presentation. These reclassifications have no impact on previously reported net income.
	With respect to the unaudited financial information of the Company as of March 31, 2015 and for the three months ended March 31, 2015 and 2014, PricewaterhouseCoopers LLP reported that they have applied limited procedures in accordance with professional standards for a review of such information. However, their separate report dated April 24, 2015 appearing herein states that they did not audit and they do not express an opinion on that unaudited financial information. Accordingly, the degree of reliance on their report on such information should be restricted in light of the limited nature of the review procedures applied. PricewaterhouseCoopers LLP is not subject to the liability provisions of Section 11 of the Securities Act of 1933 for their report on the unaudited financial information because that report is not a “report” or a “part” of a registration statement prepared or certified by PricewaterhouseCoopers LLP within the meaning of Sections 7 and 11 of the Act.
	Recent Accounting Pronouncements
	In March 2015, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2015-03, Simplifying the Presentation of Debt Issuance Costs. The amendments in this update require that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by the amendments in this update. The guidance is effective for interim periods and annual period beginning after December 15, 2015; however early adoption is permitted. The Company does not believe the adoption of this guidance will have a material impact on its financial position, results of operations or cash flows.
	In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, as a new Topic, Accounting Standards Codification Topic 606. The new revenue recognition standard provides a five-step analysis of transactions to determine when and how revenue is recognized. The core principle of the guidance is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This ASU is effective beginning in fiscal year 2017 and can be adopted either retrospectively or as a cumulative-effect adjustment as of the date of adoption. In April 2015, the FASB proposed to delay the effective date one year, beginning in fiscal year 2018. The proposal will be subject to the FASB’s due process requirement, which includes a period for public comments. The Company is currently evaluating the effect that adopting this guidance will have on its financial position, results of operations or cash flows.

Properties_and_Equipment_Net

Properties and Equipment, Net	3 Months Ended
	Mar. 31, 2015
Property, Plant and Equipment [Abstract]
Properties and Equipment, Net	Properties and Equipment, Net
	Properties and equipment, net are comprised of the following:
	(In thousands)	March 31,			December 31,
		2015			2014
	Proved oil and gas properties	$	8,291,686		$	7,984,979
	Unproved oil and gas properties	486,562			492,208
	Gathering and pipeline systems	241,458			241,272
	Land, building and other equipment	111,090			109,758
		9,130,796			8,828,217
	Accumulated depreciation, depletion and amortization	(4,071,992		)	(3,902,506		)
		$	5,058,804		$	4,925,711
	At March 31, 2015, the Company did not have any projects that had exploratory well costs that were capitalized for a period of greater than one year after drilling.

Equity_Method_Investments

Equity Method Investments	3 Months Ended
	Mar. 31, 2015
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	Equity Method Investments
	During the three months ended March 31, 2015 and 2014, the Company made contributions of approximately $3.0 million and $5.8 million, respectively, to Constitution Pipeline Company, LLC and $2.1 million and $0.2 million, respectively, to Meade Pipeline Co LLC. There were no material earnings or losses associated with the Company's equity method investments during the three months ended March 31, 2015 and 2014.
	For further information regarding the Company’s equity method investments, refer to Note 4 of the Notes to the Consolidated Financial Statements in the Form 10-K.

Debt_and_Credit_Agreements

Debt and Credit Agreements	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Debt and Credit Agreements	Debt and Credit Agreements
	The Company’s debt and credit agreements consisted of the following:
	(In thousands)		March 31,				December 31,
			2015				2014
	7.33% weighted-average fixed rate notes		$	20,000			$	20,000
	6.51% weighted-average fixed rate notes		425,000				425,000
	9.78% fixed rate notes		67,000				67,000
	5.58% weighted-average fixed rate notes		175,000				175,000
	3.65% weighted-average fixed rate notes		925,000				925,000
	Revolving credit facility		265,000				140,000
			$	1,877,000			$	1,752,000
	At March 31, 2015, the Company had $265.0 million of borrowings outstanding under its revolving credit facility at a weighted-average interest rate of 2.4% and had unused commitments of $1.1 billion. The Company’s weighted-average effective interest rate under the revolving credit facility for the three months ended March 31, 2015 and 2014 was approximately 2.6% and 2.3%, respectively.
	The Company was in compliance with all restrictive financial covenants for both the revolving credit facility and fixed rate notes as of March 31, 2015.
	Subsequent Event
	Effective April 17, 2015, the Company amended its revolving credit facility to extend the maturity date from May 2017 to April 2020 and change the mechanism under which interest rate margins are determined for outstanding borrowings. The revolving credit facility, as amended, provides for an increase in the borrowing base from $3.1 billion to $3.4 billion and an increase in commitments from $1.4 billion to $1.8 billion. The amended credit facility also provides for an accordion feature, which allows the Company to increase the available credit line up to an additional $500 million if one or more of the existing or new banks agree to provide such increased amount. The borrowing base is redetermined annually under the terms of the revolving credit facility on April 1. In addition, either the Company or the banks may request an interim redetermination twice a year or in conjunction with certain acquisitions or sales of oil and gas properties.
	Interest rates under the amended credit facility are based on Eurodollar (LIBOR) or alternate base rate (ABR) indications, plus a margin. The associated margins are based on the Company's leverage ratio as shown below:
		Leverage Ratio(1)
		<1.0x			≥1.0x and <2.0x			≥2.0x and <3.0x		≥3.0x
	Eurodollar loans	1.5	%		1.75	%		2	%	2.25	%
	ABR loans	0.5	%		0.75	%		1	%	1.25	%
	(1) The ratio of debt and other liabilities to Consolidated EBITDAX, as defined in the credit agreement.
	Upon the Company achieving an investment grade rating from either Moody's or S&P, the associated margins will be adjusted and determined based on the Company's respective credit rating on a prospective basis.
	The amended credit facility also provides for a commitment fee on the unused available balance at annual rates ranging from 0.30% to 0.50%.
	The other terms and conditions of the amended facility are generally consistent with the terms and conditions of the revolving credit facility prior to its amendment as disclosed in Note 5 of the Notes to the Consolidated Financial Statements in the Form 10-K.

Derivative_Instruments_and_Hed

Derivative Instruments and Hedging Activities	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities
	The Company periodically enters into commodity derivatives to manage its exposure to price fluctuations on natural gas and crude oil production. The Company’s credit agreement restricts the ability of the Company to enter into commodity derivatives other than to hedge or mitigate risks to which the Company has actual or projected exposure or as permitted under the Company’s risk management policies and where such derivatives do not subject the Company to material speculative risks. All of the Company’s derivatives are used for risk management purposes and are not held for trading purposes.
	Through March 31, 2014, the Company elected to designate its commodity derivatives as cash flow hedges for accounting purposes. Effective April 1, 2014, the Company elected to discontinue hedge accounting for its commodity derivatives on a prospective basis. As a result of discontinuing hedge accounting, the unrealized loss included in accumulated other comprehensive income (loss) as of April 1, 2014 of $73.4 million ($44.2 million net of tax) was frozen and reclassified into natural gas and crude oil and condensate revenues in the Condensed Consolidated Statement of Operations throughout the remainder of 2014 as the underlying hedged transactions occurred. As of March 31, 2015 and December 31, 2014, there were no gains or losses deferred in accumulated other comprehensive income (loss) associated with the Company's commodity derivatives.
	As of March 31, 2015, the Company had the following outstanding commodity derivatives:
								Collars									Swaps
								Floor						Ceiling
	Type of Contract	Volume				Contract Period		Range		Weighted-Average				Range	Weighted- Average		Weighted- Average
	Natural gas	53.4		Bcf		Apr. 2015 - Dec. 2015		$3.86 - $3.91		$	3.87			$4.27 - $4.43	$	4.35
	Natural gas	53.4		Bcf		Apr. 2015 - Dec. 2015											$	3.92
	Natural gas	31.2		Bcf		Apr. 2015 - Oct. 2015											$	3.36
	In the table above, natural gas prices are stated per Mcf.
	Effect of Derivative Instruments on the Condensed Consolidated Balance Sheet
				Fair Values of Derivative Instruments
				Derivative Assets								Derivative Liabilities
	(In thousands)	Balance Sheet Location		March 31,				December 31,				March 31,			December 31,
				2015				2014				2015			2014
	Commodity contracts	Derivative instruments (current assets)		$	134,041			$	137,603			$	—		$	—
	Offsetting of Derivative Assets and Liabilities in the Condensed Consolidated Balance Sheet
	(In thousands)	March 31,				December 31,
		2015				2014
	Derivative Assets
	Gross amounts of recognized assets	$	134,041			$	137,603
	Gross amounts offset in the statement of financial position	—				—
	Net amounts of assets presented in the statement of financial position	134,041				137,603
	Gross amounts of financial instruments not offset in the statement of financial position	—				2,338
	Net amount	$	134,041			$	139,941
	Effect of Derivative Instruments on Accumulated Other Comprehensive Income (Loss)
	The amount of gain (loss) recognized in accumulated other comprehensive income (loss) on derivatives (effective portion) is as follows:
		Three Months Ended
		March 31,
	(In thousands)	2015				2014
	Commodity contracts	$	—			$	(133,310	)
	The amount of gain (loss) reclassified from accumulated other comprehensive income (loss) into income (effective portion) is as follows:
		Three Months Ended
		March 31,
	(In thousands)	2015				2014
	Natural gas revenues	$	—			$	(70,557	)
	Crude oil and condensate revenues	—				(218		)
		$	—			$	(70,775	)
	Effect of Derivative Instruments on the Condensed Consolidated Statement of Operations
		Three Months Ended
		March 31,
	(In thousands)	2015				2014
	Derivatives Designated as Hedges
	Realized
	Natural gas	$	—			$	(70,557	)
	Crude oil and condensate	—				(218		)
		$	—			$	(70,775	)
	Derivatives Not Designated as Hedges
	Realized
	Gain (loss) on derivative instruments	37,685				—
	Unrealized
	Gain (loss) on derivative instruments	(3,562		)		—
		$	34,123			$	—
		$	34,123			$	(70,775	)
	For the three months ended March 31, 2014, there was no ineffectiveness recorded in the Condensed Consolidated Statement of Operations related to derivative instruments designated as cash flow hedges.
	Additional Disclosures about Derivative Instruments and Hedging Activities
	The use of derivative instruments involves the risk that the counterparties will be unable to meet their obligations under the agreements. The Company’s counterparties are primarily commercial banks and financial service institutions that management believes present minimal credit risk and its derivative contracts are with multiple counterparties to minimize its exposure to any individual counterparty. The Company performs both quantitative and qualitative assessments of these counterparties based on their credit ratings and credit default swap rates where applicable. The Company has not incurred any losses related to non-performance risk of its counterparties and does not anticipate any material impact on its financial results due to non-performance by third parties.
	Certain counterparties to the Company’s derivative instruments are also lenders under its revolving credit facility. The Company’s revolving credit facility and derivative instruments contain certain cross default and acceleration provisions that may require immediate payment of its derivative liabilities in certain situations. The Company also has netting arrangements with each of its counterparties that allow it to offset assets and liabilities from separate derivative contracts with that counterparty.

Fair_Value_Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements
	The Company follows the authoritative guidance for measuring fair value of assets and liabilities in its financial statements. For further information regarding the fair value hierarchy, refer to Note 1 of the Notes to the Consolidated Financial Statements in the Form 10-K.
	Non-Financial Assets and Liabilities
	The Company discloses or recognizes its non-financial assets and liabilities, such as impairments, at fair value on a nonrecurring basis. As none of the Company’s non-financial assets and liabilities were measured at fair value as of March 31, 2015 and 2014, additional disclosures were not required.
	The estimated fair value of the Company’s asset retirement obligations at inception is determined by utilizing the income approach by applying a credit-adjusted risk-free rate, which takes into account the Company’s credit risk, the time value of money, and the current economic state, to the undiscounted expected abandonment cash flows. Given the unobservable nature of the inputs, the measurement of the asset retirement obligations was classified as Level 3 in the fair value hierarchy.
	Financial Assets and Liabilities
	The following fair value hierarchy table presents information about the Company’s financial assets and liabilities measured at fair value on a recurring basis:
	(In thousands)	Quoted Prices in			Significant Other			Significant		Balance at
		Active Markets for			Observable Inputs			Unobservable Inputs		31-Mar-15
		Identical Assets			(Level 2)			(Level 3)
		(Level 1)
	Assets
	Deferred compensation plan	$	13,322		$	—		$	—	$	13,322
	Derivative contracts	—			50,716			83,325		134,041
	Total assets	$	13,322		$	50,716		$	83,325	$	147,363
	Liabilities
	Deferred compensation plan	$	29,096		$	—		$	—	$	29,096
	Total liabilities	$	29,096		$	—		$	—	$	29,096
	(In thousands)	Quoted Prices in			Significant Other			Significant		Balance at
		Active Markets for			Observable Inputs			Unobservable Inputs		31-Dec-14
		Identical Assets			(Level 2)			(Level 3)
		(Level 1)
	Assets
	Deferred compensation plan	$	13,115		$	—		$	—	$	13,115
	Derivative contracts	—			51,645			85,958		137,603
	Total assets	$	13,115		$	51,645		$	85,958	$	150,718
	Liabilities
	Deferred compensation plan	$	28,932		$	—		$	—	$	28,932
	Total liabilities	$	28,932		$	—		$	—	$	28,932
	The Company’s investments associated with its deferred compensation plan consist of mutual funds and deferred shares of the Company’s common stock that are publicly traded and for which market prices are readily available.
	The derivative instruments were measured based on quotes from the Company’s counterparties. Such quotes have been derived using an income approach that considers various inputs including current market and contractual prices for the underlying instruments, quoted forward commodity prices, basis differentials, volatility factors and interest rates, such as a LIBOR curve for a similar length of time as the derivative contract term as applicable. Estimates are verified using relevant NYMEX futures contracts and/or are compared to multiple quotes obtained from counterparties for reasonableness. The determination of the fair values presented above also incorporates a credit adjustment for non-performance risk. The Company measured the non-performance risk of its counterparties by reviewing credit default swap spreads for the various financial institutions with which it has derivative transactions, while non-performance risk of the Company is evaluated using a market credit spread provided by the Company’s bank.
	The most significant unobservable inputs relative to the Company’s Level 3 derivative contracts are basis differentials and volatility factors. An increase (decrease) in these unobservable inputs would result in an increase (decrease) in fair value, respectively. The Company does not have access to the specific assumptions used in its counterparties’ valuation models. Consequently, additional disclosures regarding significant Level 3 unobservable inputs were not provided.
	The following table sets forth a reconciliation of changes in the fair value of financial assets and liabilities classified as Level 3 in the fair value hierarchy:
		Three Months Ended
		March 31,
	(In thousands)	2015			2014
	Balance at beginning of period	$	85,958		$	(3,910	)
	Total gains (losses) (realized or unrealized):
	Realized and unrealized gains (losses) included in earnings	17,840			(62,285		)
	Included in other comprehensive income	—			(56,458		)
	Settlements	(20,473		)	62,285
	Transfers in and/or out of Level 3	—			—
	Balance at end of period	$	83,325		$	(60,368	)
	Change in unrealized gains (losses) relating to assets and liabilities still held at the end of the period	$	(2,633	)	$	—
	There were no transfers between Level 1 and Level 2 measurements for the three months ended March 31, 2015 and 2014.
	Fair Value of Other Financial Instruments
	The estimated fair value of financial instruments is the amount at which the instrument could be exchanged currently between willing parties. The carrying amount reported in the Condensed Consolidated Balance Sheet for cash and cash equivalents approximates fair value due to the short-term maturities of these instruments. Cash and cash equivalents are classified as Level 1 in the fair value hierarchy.
	The Company uses available market data and valuation methodologies to estimate the fair value of debt. The fair value of debt is the estimated amount the Company would have to pay a third party to assume the debt, including a credit spread for the difference between the issue rate and the period end market rate. The credit spread is the Company’s default or repayment risk. The credit spread (premium or discount) is determined by comparing the Company’s fixed-rate notes and revolving credit facility to new issuances (secured and unsecured) and secondary trades of similar size and credit statistics for both public and private debt. The fair value of all fixed-rate notes and the revolving credit facility is based on interest rates currently available to the Company. The Company’s debt is valued using an income approach and classified as Level 3 in the fair value hierarchy.
	The carrying amounts and fair values of debt are as follows:
		31-Mar-15						31-Dec-14
	(In thousands)	Carrying			Estimated Fair			Carrying		Estimated Fair
		Amount			Value			Amount		Value
	Debt	$	1,877,000		$	1,976,946		$	1,752,000	$	1,850,867

Asset_Retirement_Obligations

Asset Retirement Obligations	3 Months Ended
	Mar. 31, 2015
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligations	Asset Retirement Obligations
	Activity related to the Company’s asset retirement obligations is as follows:
	(In thousands)	Three Months Ended
		March 31, 2015
	Balance at beginning of period	$	126,655
	Liabilities incurred	4,355
	Liabilities settled	(113		)
	Accretion expense	1,644
	Balance at end of period	$	132,541
	As of both March 31, 2015 and December 31, 2014, approximately $2.0 million is included in accrued liabilities in the Condensed Consolidated Balance Sheet, which represents the current portion of the Company’s asset retirement obligations.

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies
	Contractual Obligations
	The Company has various contractual obligations in the normal course of its operations. There have been no material changes to the Company’s contractual obligations described under “Transportation and Gathering Agreements”, “Drilling Rig Commitments” and “Lease Commitments” as disclosed in Note 9 in the Notes to Consolidated Financial Statements included in the Form 10-K.
	Legal Matters
	Enexco Litigation
	In October 2010, the Company was sued in the Texas District Court in Shelby County, Texas by a group of plaintiffs led by Enexco, Inc. The plaintiffs alleged that the Company was negligent and grossly negligent in conducting drilling operations on a natural gas well in Shelby County, Texas in which the plaintiffs were drilling participants in 2009. The plaintiffs alleged that negligence in the Company’s drilling operations damaged not only that well, but also two nearby natural gas wells in which the plaintiffs owned interests. The plaintiffs sought damages for lost reserves of all three wells, costs of operations and associated facilities and attorneys’ fees, as well as exemplary damages based upon claims of gross negligence. The Company denied that its drilling operations were negligent and vigorously disputed both the merits of plaintiffs’ claims and their allegations of damages.
	In April 2015, the Company and the plaintiffs reached a settlement resulting in a release of all claims with regards to this matter. The settlement amount was not material to the Company’s financial position, results of operations or cash flows.
	Other
	The Company is a defendant in various legal proceedings arising in the normal course of business. All known liabilities are accrued when management determines they are probable based on its best estimate of the potential loss. While the outcome and impact of these legal proceedings on the Company cannot be predicted with certainty, management believes that the resolution of these proceedings will not have a material effect on the Company’s financial position, results of operations or cash flows.
	Contingency Reserves
	When deemed necessary, the Company establishes reserves for certain legal proceedings. The establishment of a reserve is based on an estimation process that includes the advice of legal counsel and subjective judgment of management. While management believes these reserves to be adequate, it is reasonably possible that the Company could incur additional losses with respect to those matters in which reserves have been established. The Company believes that any such amount above the amounts accrued is not material to the Condensed Consolidated Financial Statements. Future changes in facts and circumstances not currently foreseeable could result in the actual liability exceeding the estimated ranges of loss and amounts accrued.

Postretirement_Benefits

Postretirement Benefits	3 Months Ended
	Mar. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Postretirement Benefits	Postretirement Benefits
	The components of net periodic benefit costs, included in general and administrative expense in the Condensed Consolidated Statement of Operations, were as follows:
		Three Months Ended
		March 31,
	(In thousands)	2015		2014
	Service cost	$	428	$	456
	Interest cost	365		407
		$	793	$	863

Stockbased_Compensation

Stock-based Compensation	3 Months Ended
	Mar. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based Compensation	Stock-based Compensation
	General
	Stock-based compensation expense during the first three months of 2015 and 2014 was $5.9 million and $3.2 million, respectively, and is included in general and administrative expense in the Condensed Consolidated Statement of Operations.
	During the first three months of 2015 and 2014, the Company realized a $3.4 million and $16.0 million tax benefit related to the federal tax deduction in excess of book compensation cost for employee stock-based compensation, respectively. The Company is able to recognize this tax benefit only to the extent it reduces the Company’s income taxes payable.
	Refer to Note 13 of the Notes to the Consolidated Financial Statements in the Form 10-K for further description of the various types of stock-based compensation awards and the applicable award terms.
	Restricted Stock Awards
	During the first three months of 2015, 2,400 restricted stock awards were granted to employees with a grant date per share value of $27.53. The fair value of restricted stock grants is based on the closing stock price on the grant date. The Company used an annual forfeiture rate assumption of 5.0% for purposes of recognizing stock-based compensation expense for restricted stock awards.
	Restricted Stock Units
	During the first three months of 2015, 45,450 restricted stock units were granted to non-employee directors of the Company with a weighted-average grant date per unit value of $27.76. The fair value of these units is measured based on the closing stock price on grant date and compensation expense is recorded immediately. These units immediately vest and are issued when the director ceases to be a director of the Company.
	Performance Share Awards
	The performance period for the awards granted in 2015 commenced on January 1, 2015 and ends on December 31, 2017.  The Company used an annual forfeiture rate assumption ranging from 0% to 5% for purposes of recognizing stock-based compensation expense for its performance share awards.
	Performance Share Awards Based on Internal Performance Metrics
	The fair value of performance award grants based on internal performance metrics is based on the closing stock price on the grant date and represents the right to receive up to 100% of the award in shares of common stock.
	Employee Performance Share Awards. During the first three months of 2015, 349,780 Employee Performance Share Awards were granted at a grant date per share value of $27.71. The performance metrics are set by the Company’s compensation committee and are based on the Company’s average production, average finding costs and average reserve replacement over a three-year performance period. Based on the Company’s probability assessment at March 31, 2015, it is considered probable that the criteria for these awards will be met.
	Hybrid Performance Share Awards. During the first three months of 2015, 194,947 Hybrid Performance Share Awards were granted at a grant date per share value of $27.71. The 2015 awards vest 25% on each of the first and second anniversary dates and 50% on the third anniversary, provided that the Company has $100 million or more of operating cash flow for the year preceding the vesting date, as set by the Company’s compensation committee. If the Company does not meet the performance metric for the applicable period, then the portion of the performance shares that would have been issued on that anniversary date will be forfeited. Based on the Company’s probability assessment at March 31, 2015, it is considered probable that the criteria for these awards will be met.
	Performance Share Awards Based on Market Conditions
	These awards have both an equity and liability component, with the right to receive up to the first 100% of the award in shares of common stock and the right to receive up to an additional 100% of the value of the award in excess of the equity component in cash. The equity portion of these awards is valued on the grant date and is not marked to market, while the liability portion of the awards is valued as of the end of each reporting period on a mark-to-market basis. The Company calculates the fair value of the equity and liability portions of the awards using a Monte Carlo simulation model.
	TSR Performance Share Awards.  During the first three months of 2015, 292,421 TSR Performance Share Awards were granted and are earned, or not earned, based on the comparative performance of the Company’s common stock measured against a predetermined group of companies in the Company’s peer group over a three-year performance period.
	The following assumptions were used to determine the grant date fair value of the equity component (February 19, 2015) and the period-end fair value of the liability component of the TSR Performance Share Awards:
			Grant Date			31-Mar-15
	Fair value per performance share award		$	19.29		$10.37 - $14.21
	Assumptions:
	Stock price volatility		32.3		%	29.3% - 30.3%
	Risk free rate of return		1		%	0.2% - 0.8%
	Expected dividend yield		0.3		%	0.3	%
	Supplemental Employee Incentive Plan
	The Company recognized stock-based compensation (benefit) expense of $(0.1) million and $1.5 million for the three months ended March 31, 2015 and 2014, respectively, related to the Company’s Supplemental Employee Incentive Plan, which is included in general and administrative expense in the Condensed Consolidated Statement of Operations. Refer to Note 13 of the Notes to the Consolidated Financial Statements in the Form 10-K for additional information on the provisions of the Plan.
	The following assumptions were used to determine the period-end fair value of the Supplemental Employee Incentive Plan IV liability using a Monte Carlo simulation model:
		March 31,
		2015
	Stock price volatility	31.3	%
	Risk free rate of return	0.7	%
	Annual salary increase rate	4	%
	Annual turnover rate	4.6	%

Earnings_per_Common_Share

Earnings per Common Share	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Earnings per Common Share	Earnings per Common Share
	Basic earnings per share (EPS) is computed by dividing net income by the weighted-average number of common shares outstanding for the period. Diluted EPS is similarly calculated except that the common shares outstanding for the period is increased using the treasury stock method to reflect the potential dilution that could occur if outstanding stock appreciation rights were exercised and stock awards were vested at the end of the applicable period.
	The following is a calculation of basic and diluted weighted-average shares outstanding:
		Three Months Ended
		March 31,
	(In thousands)	2015	2014
	Weighted-average shares - basic	413,344	416,900
	Dilution effect of stock appreciation rights and stock awards at end of period	1,427	1,613
	Weighted-average shares - diluted	414,771	418,513
	Weighted-average stock awards and shares excluded from diluted EPS due to the anti-dilutive effect	401	272

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Loss)	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss)
	Amounts reclassified from accumulated other comprehensive income (loss) into the Condensed Consolidated Statement of Operations were as follows:
		Three Months Ended					Affected Line Item in the Condensed
		March 31,
	(In thousands)	2015		2014			Consolidated Statement of Operations
	Gain (Loss) on Cash Flow Hedges
	Commodity contracts	$	—	$	(70,557	)	Natural gas revenues
	Commodity contracts	—		(218		)	Crude oil and condensate revenues
		—		(70,775		)	Total before tax
		—		28,210			Tax benefit (expense)
	Total reclassifications for the period	$	—	$	(42,565	)	Net of tax

ADDITIONAL_BALANCE_SHEET_INFOR

ADDITIONAL BALANCE SHEET INFORMATION	3 Months Ended
	Mar. 31, 2015
Balance Sheet Related Disclosures [Abstract]
ADDITIONAL BALANCE SHEET INFORMATION	ADDITIONAL BALANCE SHEET INFORMATION
	Certain balance sheet amounts are comprised of the following:
	(In thousands)	March 31,			December 31,
		2015			2014
	Accounts receivable, net
	Trade accounts	$	182,863		$	227,835
	Joint interest accounts	2,016			2,245
	Income taxes receivable	2,441			3,612
	Other accounts	(614		)	6,515
		186,706			240,207
	Allowance for doubtful accounts	(1,425		)	(1,198		)
		$	185,281		$	239,009
	Inventories
	Natural gas in storage	$	2,394		$	3,281
	Tubular goods and well equipment	11,535			10,675
	Other accounts	158			70
		$	14,087		$	14,026
	Other assets
	Deferred compensation plan	$	13,322		$	13,115
	Debt issuance cost	16,082			17,349
	Other accounts	184			65
		$	29,588		$	30,529
	Accounts payable
	Trade accounts	$	68,891		$	54,949
	Natural gas purchases	2,164			2,407
	Royalty and other owners	93,316			97,298
	Accrued capital costs	130,782			222,426
	Taxes other than income	20,464			16,806
	Drilling advances	87			88
	Other accounts	5,511			6,102
		$	321,215		$	400,076
	Accrued liabilities
	Employee benefits	$	10,819		$	22,815
	Taxes other than income	7,455			7,128
	Interest payable	13,755			30,677
	Other accounts	2,550			3,049
		$	34,579		$	63,669
	Other liabilities
	Deferred compensation plan	$	29,096		$	28,932
	Other accounts	9,312			10,675
		$	38,408		$	39,607

Financial_Statement_Presentati1

Financial Statement Presentation (Policies)	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements
	In March 2015, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2015-03, Simplifying the Presentation of Debt Issuance Costs. The amendments in this update require that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by the amendments in this update. The guidance is effective for interim periods and annual period beginning after December 15, 2015; however early adoption is permitted. The Company does not believe the adoption of this guidance will have a material impact on its financial position, results of operations or cash flows.
	In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, as a new Topic, Accounting Standards Codification Topic 606. The new revenue recognition standard provides a five-step analysis of transactions to determine when and how revenue is recognized. The core principle of the guidance is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. This ASU is effective beginning in fiscal year 2017 and can be adopted either retrospectively or as a cumulative-effect adjustment as of the date of adoption. In April 2015, the FASB proposed to delay the effective date one year, beginning in fiscal year 2018. The proposal will be subject to the FASB’s due process requirement, which includes a period for public comments. The Company is currently evaluating the effect that adopting this guidance will have on its financial position, results of operations or cash flows.

Properties_and_Equipment_Net_T

Properties and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2015
Property, Plant and Equipment [Abstract]
Schedule of properties and equipment, net	Properties and equipment, net are comprised of the following:
	(In thousands)	March 31,			December 31,
		2015			2014
	Proved oil and gas properties	$	8,291,686		$	7,984,979
	Unproved oil and gas properties	486,562			492,208
	Gathering and pipeline systems	241,458			241,272
	Land, building and other equipment	111,090			109,758
		9,130,796			8,828,217
	Accumulated depreciation, depletion and amortization	(4,071,992		)	(3,902,506		)
		$	5,058,804		$	4,925,711

Debt_and_Credit_Agreements_Tab

Debt and Credit Agreements (Tables)	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Debt and credit agreement components	The Company’s debt and credit agreements consisted of the following:
	(In thousands)		March 31,				December 31,
			2015				2014
	7.33% weighted-average fixed rate notes		$	20,000			$	20,000
	6.51% weighted-average fixed rate notes		425,000				425,000
	9.78% fixed rate notes		67,000				67,000
	5.58% weighted-average fixed rate notes		175,000				175,000
	3.65% weighted-average fixed rate notes		925,000				925,000
	Revolving credit facility		265,000				140,000
			$	1,877,000			$	1,752,000
Changes in basis spread on variable rate based on changes in leverage ratio	Interest rates under the amended credit facility are based on Eurodollar (LIBOR) or alternate base rate (ABR) indications, plus a margin. The associated margins are based on the Company's leverage ratio as shown below:
		Leverage Ratio(1)
		<1.0x			≥1.0x and <2.0x			≥2.0x and <3.0x		≥3.0x
	Eurodollar loans	1.5	%		1.75	%		2	%	2.25	%
	ABR loans	0.5	%		0.75	%		1	%	1.25	%
	(1) The ratio of debt and other liabilities to Consolidated EBITDAX, as defined in the credit agreement.

Derivative_Instruments_and_Hed1

Derivative Instruments and Hedging Activities (Tables)	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Outstanding commodity derivatives	As of March 31, 2015, the Company had the following outstanding commodity derivatives:
								Collars									Swaps
								Floor						Ceiling
	Type of Contract	Volume				Contract Period		Range		Weighted-Average				Range	Weighted- Average		Weighted- Average
	Natural gas	53.4		Bcf		Apr. 2015 - Dec. 2015		$3.86 - $3.91		$	3.87			$4.27 - $4.43	$	4.35
	Natural gas	53.4		Bcf		Apr. 2015 - Dec. 2015											$	3.92
	Natural gas	31.2		Bcf		Apr. 2015 - Oct. 2015											$	3.36
Effect of derivative instruments on the condensed consolidated balance sheet	Effect of Derivative Instruments on the Condensed Consolidated Balance Sheet
				Fair Values of Derivative Instruments
				Derivative Assets								Derivative Liabilities
	(In thousands)	Balance Sheet Location		March 31,				December 31,				March 31,			December 31,
				2015				2014				2015			2014
	Commodity contracts	Derivative instruments (current assets)		$	134,041			$	137,603			$	—		$	—
Schedule of offsetting of derivative assets and liabilities in the condensed consolidated balance sheet	Offsetting of Derivative Assets and Liabilities in the Condensed Consolidated Balance Sheet
	(In thousands)	March 31,				December 31,
		2015				2014
	Derivative Assets
	Gross amounts of recognized assets	$	134,041			$	137,603
	Gross amounts offset in the statement of financial position	—				—
	Net amounts of assets presented in the statement of financial position	134,041				137,603
	Gross amounts of financial instruments not offset in the statement of financial position	—				2,338
	Net amount	$	134,041			$	139,941
Amount of gain (loss) recognized in accumulated other comprehensive income (loss) on derivatives	The amount of gain (loss) recognized in accumulated other comprehensive income (loss) on derivatives (effective portion) is as follows:
		Three Months Ended
		March 31,
	(In thousands)	2015				2014
	Commodity contracts	$	—			$	(133,310	)
Amount of gain (loss) reclassified from accumulated other comprehensive income (loss)	The amount of gain (loss) reclassified from accumulated other comprehensive income (loss) into income (effective portion) is as follows:
		Three Months Ended
		March 31,
	(In thousands)	2015				2014
	Natural gas revenues	$	—			$	(70,557	)
	Crude oil and condensate revenues	—				(218		)
		$	—			$	(70,775	)
Effect of derivatives not designated as hedging instruments on the condensed consolidated statement of operations	Effect of Derivative Instruments on the Condensed Consolidated Statement of Operations
		Three Months Ended
		March 31,
	(In thousands)	2015				2014
	Derivatives Designated as Hedges
	Realized
	Natural gas	$	—			$	(70,557	)
	Crude oil and condensate	—				(218		)
		$	—			$	(70,775	)
	Derivatives Not Designated as Hedges
	Realized
	Gain (loss) on derivative instruments	37,685				—
	Unrealized
	Gain (loss) on derivative instruments	(3,562		)		—
		$	34,123			$	—
		$	34,123			$	(70,775	)

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Financial assets and liabilities measured at fair value on a recurring basis	The following fair value hierarchy table presents information about the Company’s financial assets and liabilities measured at fair value on a recurring basis:
	(In thousands)	Quoted Prices in			Significant Other			Significant		Balance at
		Active Markets for			Observable Inputs			Unobservable Inputs		31-Mar-15
		Identical Assets			(Level 2)			(Level 3)
		(Level 1)
	Assets
	Deferred compensation plan	$	13,322		$	—		$	—	$	13,322
	Derivative contracts	—			50,716			83,325		134,041
	Total assets	$	13,322		$	50,716		$	83,325	$	147,363
	Liabilities
	Deferred compensation plan	$	29,096		$	—		$	—	$	29,096
	Total liabilities	$	29,096		$	—		$	—	$	29,096
	(In thousands)	Quoted Prices in			Significant Other			Significant		Balance at
		Active Markets for			Observable Inputs			Unobservable Inputs		31-Dec-14
		Identical Assets			(Level 2)			(Level 3)
		(Level 1)
	Assets
	Deferred compensation plan	$	13,115		$	—		$	—	$	13,115
	Derivative contracts	—			51,645			85,958		137,603
	Total assets	$	13,115		$	51,645		$	85,958	$	150,718
	Liabilities
	Deferred compensation plan	$	28,932		$	—		$	—	$	28,932
	Total liabilities	$	28,932		$	—		$	—	$	28,932
Fair value of net financial assets and liabilities classified as level 3	The following table sets forth a reconciliation of changes in the fair value of financial assets and liabilities classified as Level 3 in the fair value hierarchy:
		Three Months Ended
		March 31,
	(In thousands)	2015			2014
	Balance at beginning of period	$	85,958		$	(3,910	)
	Total gains (losses) (realized or unrealized):
	Realized and unrealized gains (losses) included in earnings	17,840			(62,285		)
	Included in other comprehensive income	—			(56,458		)
	Settlements	(20,473		)	62,285
	Transfers in and/or out of Level 3	—			—
	Balance at end of period	$	83,325		$	(60,368	)
	Change in unrealized gains (losses) relating to assets and liabilities still held at the end of the period	$	(2,633	)	$	—
Carrying amounts and fair values of long-term debt	The carrying amounts and fair values of debt are as follows:
		31-Mar-15						31-Dec-14
	(In thousands)	Carrying			Estimated Fair			Carrying		Estimated Fair
		Amount			Value			Amount		Value
	Debt	$	1,877,000		$	1,976,946		$	1,752,000	$	1,850,867

Asset_Retirement_Obligations_T

Asset Retirement Obligations (Tables)	3 Months Ended
	Mar. 31, 2015
Asset Retirement Obligation Disclosure [Abstract]
Activity Related to Asset Retirement Obligations	Activity related to the Company’s asset retirement obligations is as follows:
	(In thousands)	Three Months Ended
		March 31, 2015
	Balance at beginning of period	$	126,655
	Liabilities incurred	4,355
	Liabilities settled	(113		)
	Accretion expense	1,644
	Balance at end of period	$	132,541

Postretirement_Benefits_Tables

Postretirement Benefits (Tables)	3 Months Ended
	Mar. 31, 2015
Compensation and Retirement Disclosure [Abstract]
Components of net periodic benefit costs	The components of net periodic benefit costs, included in general and administrative expense in the Condensed Consolidated Statement of Operations, were as follows:
		Three Months Ended
		March 31,
	(In thousands)	2015		2014
	Service cost	$	428	$	456
	Interest cost	365		407
		$	793	$	863

Stockbased_Compensation_Tables

Stock-based Compensation (Tables)	3 Months Ended
	Mar. 31, 2015
Supplemental Employee Incentive Plan IV
Stock-Based Compensation arrangements
Schedule of Value per Share and Assumptions Used	The following assumptions were used to determine the period-end fair value of the Supplemental Employee Incentive Plan IV liability using a Monte Carlo simulation model:
		March 31,
		2015
	Stock price volatility	31.3	%
	Risk free rate of return	0.7	%
	Annual salary increase rate	4	%
	Annual turnover rate	4.6	%
TSR Performance Share Awards
Stock-Based Compensation arrangements
Schedule of Value per Share and Assumptions Used	The following assumptions were used to determine the grant date fair value of the equity component (February 19, 2015) and the period-end fair value of the liability component of the TSR Performance Share Awards:
			Grant Date			31-Mar-15
	Fair value per performance share award		$	19.29		$10.37 - $14.21
	Assumptions:
	Stock price volatility		32.3		%	29.3% - 30.3%
	Risk free rate of return		1		%	0.2% - 0.8%
	Expected dividend yield		0.3		%	0.3	%

Earnings_per_Common_Share_Tabl

Earnings per Common Share (Tables)	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Calculation of basic and diluted weighted-average shares outstanding
		Three Months Ended
		March 31,
	(In thousands)	2015	2014
	Weighted-average shares - basic	413,344	416,900
	Dilution effect of stock appreciation rights and stock awards at end of period	1,427	1,613
	Weighted-average shares - diluted	414,771	418,513
	Weighted-average stock awards and shares excluded from diluted EPS due to the anti-dilutive effect	401	272

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Loss) (Tables)	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Schedule of amount reclassified from accumulated other comprehensive income (loss) into the Condensed Consolidated Statement of Operations	Amounts reclassified from accumulated other comprehensive income (loss) into the Condensed Consolidated Statement of Operations were as follows:
		Three Months Ended					Affected Line Item in the Condensed
		March 31,
	(In thousands)	2015		2014			Consolidated Statement of Operations
	Gain (Loss) on Cash Flow Hedges
	Commodity contracts	$	—	$	(70,557	)	Natural gas revenues
	Commodity contracts	—		(218		)	Crude oil and condensate revenues
		—		(70,775		)	Total before tax
		—		28,210			Tax benefit (expense)
	Total reclassifications for the period	$	—	$	(42,565	)	Net of tax

ADDITIONAL_BALANCE_SHEET_INFOR1

ADDITIONAL BALANCE SHEET INFORMATION (Tables)	3 Months Ended
	Mar. 31, 2015
Balance Sheet Related Disclosures [Abstract]
Additional Balance Sheet Information	Certain balance sheet amounts are comprised of the following:
	(In thousands)	March 31,			December 31,
		2015			2014
	Accounts receivable, net
	Trade accounts	$	182,863		$	227,835
	Joint interest accounts	2,016			2,245
	Income taxes receivable	2,441			3,612
	Other accounts	(614		)	6,515
		186,706			240,207
	Allowance for doubtful accounts	(1,425		)	(1,198		)
		$	185,281		$	239,009
	Inventories
	Natural gas in storage	$	2,394		$	3,281
	Tubular goods and well equipment	11,535			10,675
	Other accounts	158			70
		$	14,087		$	14,026
	Other assets
	Deferred compensation plan	$	13,322		$	13,115
	Debt issuance cost	16,082			17,349
	Other accounts	184			65
		$	29,588		$	30,529
	Accounts payable
	Trade accounts	$	68,891		$	54,949
	Natural gas purchases	2,164			2,407
	Royalty and other owners	93,316			97,298
	Accrued capital costs	130,782			222,426
	Taxes other than income	20,464			16,806
	Drilling advances	87			88
	Other accounts	5,511			6,102
		$	321,215		$	400,076
	Accrued liabilities
	Employee benefits	$	10,819		$	22,815
	Taxes other than income	7,455			7,128
	Interest payable	13,755			30,677
	Other accounts	2,550			3,049
		$	34,579		$	63,669
	Other liabilities
	Deferred compensation plan	$	29,096		$	28,932
	Other accounts	9,312			10,675
		$	38,408		$	39,607

Properties_and_Equipment_Net_D

Properties and Equipment, Net (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Property, Plant and Equipment [Abstract]
Proved oil and gas properties	$8,291,686	$7,984,979
Unproved oil and gas properties	486,562	492,208
Gathering and pipeline systems	241,458	241,272
Land, building and other equipment	111,090	109,758
Properties and equipment, gross, total	9,130,796	8,828,217
Accumulated depreciation, depletion and amortization	-4,071,992	-3,902,506
Properties and equipment, net	$5,058,804	$4,925,711

Properties_and_Equipment_Net_D1

Properties and Equipment, Net (Details 2)	3 Months Ended
	Mar. 31, 2015
Property, Plant and Equipment [Abstract]
Minimum term of capitalization of exploratory well costs	1 year

Equity_Method_Investments_Deta

Equity Method Investments (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Constitution Pipeline Company, LLC
Equity Method Investment
Contributions made to equity method investments	$3	$5.80
Meade Pipeline Co LLC
Equity Method Investment
Contributions made to equity method investments	$2.10	$0.20

Debt_and_Credit_Agreements_Det

Debt and Credit Agreements (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Debt Instrument [Line Items]
Long-term debt	$1,877,000	$1,752,000
7.33% weighted-average fixed rate notes
Debt Instrument [Line Items]
Long-term debt	20,000	20,000
6.51% weighted-average fixed rate notes
Debt Instrument [Line Items]
Long-term debt	425,000	425,000
9.78% fixed rate notes
Debt Instrument [Line Items]
Long-term debt	67,000	67,000
5.58% weighted-average fixed rate notes
Debt Instrument [Line Items]
Long-term debt	175,000	175,000
3.65% weighted-average fixed rate notes
Debt Instrument [Line Items]
Long-term debt	925,000	925,000
Revolving credit facility
Debt Instrument [Line Items]
Long-term debt	$265,000	$140,000

Debit_and_Credit_Agreements_Ad

Debit and Credit Agreements (Additional Information) (Details)	Mar. 31, 2015	Dec. 31, 2014
7.33% weighted-average fixed rate notes
Debt Instrument [Line Items]
Long-term debt, weighted average interest rate	7.33%	7.33%
6.51% weighted-average fixed rate notes
Debt Instrument [Line Items]
Long-term debt, weighted average interest rate	6.51%	6.51%
9.78% fixed rate notes
Debt Instrument [Line Items]
Long-term debt, interest rate, stated percentage	9.78%	9.78%
5.58% weighted-average fixed rate notes
Debt Instrument [Line Items]
Long-term debt, weighted average interest rate	5.58%	5.58%
3.65% weighted-average fixed rate notes
Debt Instrument [Line Items]
Long-term debt, weighted average interest rate	3.65%	3.65%

Debt_and_Credit_Agreements_Det1

Debt and Credit Agreements (Details 2) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Debt Instrument [Line Items]
Long-term debt	$1,877,000,000		$1,752,000,000
Revolving credit facility
Debt Instrument [Line Items]
Long-term debt	265,000,000		140,000,000
Long-term debt, weighted average interest rate	2.40%
Availability under the credit facility	$1,100,000,000
Weighted-average effective interest rate	2.60%	2.30%

Debt_and_Credit_Agreements_Det2

Debt and Credit Agreements (Details 3) (Revolving credit facility, USD $)	0 Months Ended
	Apr. 17, 2015	Mar. 31, 2015	Apr. 16, 2015
Debt Instrument [Line Items]
Availability under the credit facility		$1,100,000,000
Subsequent event
Debt Instrument [Line Items]
Borrowing base	3,400,000,000		3,100,000,000
Availability under the credit facility	1,800,000,000		1,400,000,000
Subsequent event | Accordion Feature, Amended Facility
Debt Instrument [Line Items]
Borrowing base	500,000,000
Minimum | Subsequent event
Debt Instrument [Line Items]
Commitment fee on the unused available balance	0.30%
Maximum | Subsequent event
Debt Instrument [Line Items]
Commitment fee on the unused available balance	0.50%
Eurodollar LIBOR | Subsequent event
Debt Instrument [Line Items]
Description of variable rate basis	Eurodollar (LIBOR)
Alternate base rate (ABR) | Subsequent event
Debt Instrument [Line Items]
Description of variable rate basis	alternate base rate (ABR)
Debt Instrument Leverage Ratio Less than 1.0x | Eurodollar LIBOR | Subsequent event
Interest Rates Under Amended Credit Facility
Basis spread on variable rate	1.50%
Debt Instrument Leverage Ratio Less than 1.0x | Alternate base rate (ABR) | Subsequent event
Interest Rates Under Amended Credit Facility
Basis spread on variable rate	0.50%
Debt Instrument Leverage Ratio Greater than or Equal to 1.0x but Less than 2.0x | Eurodollar LIBOR | Subsequent event
Interest Rates Under Amended Credit Facility
Basis spread on variable rate	1.75%
Debt Instrument Leverage Ratio Greater than or Equal to 1.0x but Less than 2.0x | Alternate base rate (ABR) | Subsequent event
Interest Rates Under Amended Credit Facility
Basis spread on variable rate	0.75%
Debt Instrument Leverage Ratio Greater than or Equal to 2.0x but Less 3.0x | Eurodollar LIBOR | Subsequent event
Interest Rates Under Amended Credit Facility
Basis spread on variable rate	2.00%
Debt Instrument Leverage Ratio Greater than or Equal to 2.0x but Less 3.0x | Alternate base rate (ABR) | Subsequent event
Interest Rates Under Amended Credit Facility
Basis spread on variable rate	1.00%
Debt Instrument Leverage Ratio Greater than or Equal to 3.0x | Eurodollar LIBOR | Subsequent event
Interest Rates Under Amended Credit Facility
Basis spread on variable rate	2.25%
Debt Instrument Leverage Ratio Greater than or Equal to 3.0x | Alternate base rate (ABR) | Subsequent event
Interest Rates Under Amended Credit Facility
Basis spread on variable rate	1.25%

Derivative_Instruments_and_Hed2

Derivative Instruments and Hedging Activities (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Apr. 01, 2014
Derivative disclosures
Unrealized losses included in accumulated other comprehensive income and will reclassified into natural gas and crude oil revenues , pre-tax			$73,400,000
Unrealized losses included in accumulated other comprehensive income and will reclassified into natural gas and crude oil revenues , net of tax	$0	$0	$44,200,000
Derivatives Designated as Hedges | Natural Gas Collars with contract period of April 2015 - December 2015
Derivative disclosures
Volume	53,400
Derivatives Designated as Hedges | Natural Gas Collars with contract period of April 2015 - December 2015 | Minimum
Derivative disclosures
Collar Floor Price	3.86
Collar Ceiling Price	4.27
Derivatives Designated as Hedges | Natural Gas Collars with contract period of April 2015 - December 2015 | Maximum
Derivative disclosures
Collar Floor Price	3.91
Collar Ceiling Price	4.43
Derivatives Designated as Hedges | Natural Gas Collars with contract period of April 2015 - December 2015 | Weighted Average
Derivative disclosures
Collar Floor Price	3.87
Collar Ceiling Price	4.35
Derivatives Designated as Hedges | Natural Gas Swaps with contract period of April 2015 - December 2015
Derivative disclosures
Volume	53,400
Derivatives Designated as Hedges | Natural Gas Swaps with contract period of April 2015 - December 2015 | Weighted Average
Derivative disclosures
Swaps Weighted Average	3.92
Derivatives Designated as Hedges | Natural Gas Swaps with contract period of April 2015 - October 2015
Derivative disclosures
Volume	31,200
Derivatives Designated as Hedges | Natural Gas Swaps with contract period of April 2015 - October 2015 | Weighted Average
Derivative disclosures
Swaps Weighted Average	3.36

Derivative_Instruments_and_Hed3

Derivative Instruments and Hedging Activities (Details 2) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Effect of derivative instruments on the Consolidated Balance Sheet
Fair values of derivative instruments	$134,041	$137,603
Derivatives Not Designated as Hedges | Commodity contracts | Derivative instruments (current assets)
Effect of derivative instruments on the Consolidated Balance Sheet
Fair values of derivative instruments	$134,041	$137,603

Derivative_Instruments_and_Hed4

Derivative Instruments and Hedging Activities (Details 3) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Derivative Assets
Gross amounts of recognized assets	$134,041	$137,603
Gross amounts offset in the statement of financial position	0	0
Net amounts of assets presented in the statement of financial position	134,041	137,603
Gross amounts of financial instruments not offset in the statement of financial position	0	2,338
Net amount	$134,041	$139,941

Derivative_Instruments_and_Hed5

Derivative Instruments and Hedging Activities (Details 4) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Derivative instruments and hedging activities
Ineffectiveness related to derivative instruments		$0
Amount of gain (loss) reclassified from accumulated other comprehensive income (loss) into income (effective portion)	0	-70,775,000
Unrealized gain (loss) on derivative instruments	-3,562,000	0
Gain (loss) on derivative instruments	34,123,000	0
Total	34,123,000	-70,775,000
Natural Gas Revenues
Derivative instruments and hedging activities
Amount of gain (loss) reclassified from accumulated other comprehensive income (loss) into income (effective portion)	0	-70,557,000
Crude Oil and Condensate Revenues
Derivative instruments and hedging activities
Amount of gain (loss) reclassified from accumulated other comprehensive income (loss) into income (effective portion)	0	-218,000
Commodity contracts
Derivative instruments and hedging activities
Amount of gain (loss) recognized in other comprehensive income (loss) on derivative (effective portion)	0	-133,310,000
Derivatives Designated as Hedges
Derivative instruments and hedging activities
Realized gain (loss) on derivative instruments	0	-70,775,000
Derivatives Designated as Hedges | Natural Gas Revenues
Derivative instruments and hedging activities
Realized gain (loss) on derivative instruments	0	-70,557,000
Derivatives Designated as Hedges | Crude Oil and Condensate Revenues
Derivative instruments and hedging activities
Realized gain (loss) on derivative instruments	0	-218,000
Derivatives Not Designated as Hedges
Derivative instruments and hedging activities
Unrealized gain (loss) on derivative instruments	-3,562,000	0
Derivatives Not Designated as Hedges | Gain (loss) on derivative instruments
Derivative instruments and hedging activities
Realized gain (loss) on derivative instruments	$37,685,000	$0

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
	Impaired_Asset_And_Liability	Impaired_Asset_And_Liability
Assets
Deferred compensation plan	$13,322		$13,115
Derivative contracts	134,041		137,603
Total assets	147,363		150,718
Liabilities
Deferred compensation plan	29,096		28,932
Total liabilities	29,096		28,932
Number of non-financial assets and liabilities impaired	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Recurring basis
Assets
Deferred compensation plan	13,322		13,115
Derivative contracts	0		0
Total assets	13,322		13,115
Liabilities
Deferred compensation plan	29,096		28,932
Total liabilities	29,096		28,932
Significant Other Observable Inputs (Level 2) | Recurring basis
Assets
Deferred compensation plan	0		0
Derivative contracts	50,716		51,645
Total assets	50,716		51,645
Liabilities
Deferred compensation plan	0		0
Total liabilities	0		0
Significant Unobservable Inputs (Level 3) | Recurring basis
Assets
Deferred compensation plan	0		0
Derivative contracts	83,325		85,958
Total assets	83,325		85,958
Liabilities
Deferred compensation plan	0		0
Total liabilities	$0		$0

Fair_Value_Measurements_Detail1

Fair Value Measurements (Details 2) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Reconciliation of changes in the fair value of financial assets and liabilities classified as Level 3 in the fair value hierarchy
Balance at beginning of period	$85,958	($3,910)
Total gains (losses) (realized or unrealized):
Realized and unrealized gains (losses) included in earnings	17,840	-62,285
Included in other comprehensive income	0	-56,458
Settlements	-20,473	62,285
Transfers in and/or out of Level 3	0	0
Balance at end of period	83,325	-60,368
Change in unrealized gains (losses) relating to assets and liabilities still held at the end of the period	($2,633)	$0

Fair_Value_Measurements_Detail2

Fair Value Measurements (Details 3) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Fair value disclosures
Long-term debt	$1,877,000	$1,752,000
Carrying amount
Fair value disclosures
Long-term debt	1,877,000	1,752,000
Estimated fair value
Fair value disclosures
Long-term debt	$1,976,946	$1,850,867

Fair_Value_Measurements_Additi

Fair Value Measurements (Additional Information) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Fair Value Disclosures [Abstract]
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount	$0	$0
Fair Value, Liabilities, Level 1 to Level 2 Transfers, Amount	0	0
Fair Value, Assets, Level 2 to Level 1 Transfers, Amount	0	0
Fair Value, Liabilities, Level 2 to Level 1 Transfers, Amount	$0	$0

Asset_Retirement_Obligations_D

Asset Retirement Obligations (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Asset Retirement Obligation
Balance at beginning of period	$126,655,000
Liabilities incurred	4,355,000
Liabilities settled	-113,000
Accretion expense	1,644,000
Balance at end of period	132,541,000
Current portion of asset retirement obligation	$2,000,000	$2,000,000

Postretirement_Benefits_Detail

Postretirement Benefits (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Components of Net Periodic Benefit Cost
Service cost	$428	$456
Interest cost	365	407
Net periodic benefit cost	$793	$863

Stockbased_Compensation_Detail

Stock-based Compensation (Details) (USD $)	3 Months Ended		0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Feb. 20, 2014
Stock-based Compensation arrangements
Stock based compensation expense	$5,900,000	$3,200,000
Tax benefits realized for stock-based compensation	3,400,000	16,000,000
Supplemental Employee Incentive Plan IV
Stock-based Compensation arrangements
Stock based compensation expense	-100,000	1,500,000
Assumptions:
Stock price volatility	31.30%
Risk free rate of return	0.70%
Annual salary increase rate	4.00%
Annual turnover rate	4.60%
Restricted Stock Awards
Stock-based Compensation arrangements
Granted (in shares)	2,400
Granted (in dollars per share)	$27.53
Annual forfeiture rate assumption (as a percent)	5.00%
Restricted Stock Units
Stock-based Compensation arrangements
Granted (in shares)	45,450
Granted (in dollars per share)	$27.76
Performance Share Awards | Minimum
Stock-based Compensation arrangements
Annual forfeiture rate assumption (as a percent)	0.00%
Performance Share Awards | Maximum
Stock-based Compensation arrangements
Annual forfeiture rate assumption (as a percent)	5.00%
Performance Share Awards Based on Internal Performance Metrics | Maximum
Stock-based Compensation arrangements
Right to receive additional shares (as a percent)	100.00%
Employee Performance Share Awards
Stock-based Compensation arrangements
Granted (in shares)	349,780
Granted (in dollars per share)	$27.71
Number of years over which performance criteria is to be met	3 years
Hybrid Performance Share Awards
Stock-based Compensation arrangements
Granted (in shares)	194,947
Granted (in dollars per share)	$27.71
Vesting rights	The 2015 awards vest 25% on each of the first and second anniversary dates and 50% on the third anniversary
Minimum operating cash flow for the year preceding the performance period	$100,000,000
Hybrid Performance Share Awards | Hybrid performance share awards, percentage vesting on each of the first and second anniversary
Stock-based Compensation arrangements
Award vesting rights, percentage	25.00%
Hybrid Performance Share Awards | Hybrid performance share awards, percentage vesting on the third anniversary
Stock-based Compensation arrangements
Award vesting rights, percentage	50.00%
Performance Shares Based on Market Conditions | Maximum
Stock-based Compensation arrangements
Right to receive shares (as a percent)	100.00%
Right to receive an additional award in cash (as a percent)	100.00%
TSR Performance Share Awards
Stock-based Compensation arrangements
Granted (in shares)	292,421
Performance period	3 years
Assumptions:
Fair value per performance share award (in dollars per share)			$19.29
Stock price volatility			32.30%
Risk free rate of return			1.00%
Expected dividend yield	0.30%		0.30%
Stock price volatility, minimum	29.30%
Stock price volatility, maximum	30.30%
Risk free rate of return, minimum	0.20%
Risk free rate of return, maximum	0.80%
Fair value per performance share award, minimum (in dollars per share)	$10.37
Fair value per performance share award, maximum(in dollars per share)	$14.21

Earnings_per_Common_Share_Deta

Earnings per Common Share (Details)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Earnings Per Share [Abstract]
Weighted-average shares - basic	413,344	416,900
Dilution effect of stock appreciation rights and stock awards at end of period (in shares)	1,427	1,613
Weighted-average shares - diluted	414,771	418,513
Weighted-average stock awards and shares excluded from diluted EPS due to the anti-dilutive effect	401	272

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Loss) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Line items in income statement impacted by reclassifications out of accumulated other comprehensive income
Natural gas revenues	$360,191	$432,809
Crude oil and condensate revenues	62,558	59,144
Income before income taxes	63,729	177,930
Tax benefit (expense)	-23,474	-70,899
Reclassifications to net income	40,255	107,031
Amount reclassified from accumulated other comprehensive income
Line items in income statement impacted by reclassifications out of accumulated other comprehensive income
Income before income taxes	0	-70,775
Tax benefit (expense)	0	28,210
Reclassifications to net income	0	-42,565
Gain (loss) on cash flow hedges | Amount reclassified from accumulated other comprehensive income | Commodity contracts
Line items in income statement impacted by reclassifications out of accumulated other comprehensive income
Natural gas revenues	0	-70,557
Crude oil and condensate revenues	$0	($218)

ADDITIONAL_BALANCE_SHEET_INFOR2

ADDITIONAL BALANCE SHEET INFORMATION (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Accounts receivable, net
Trade accounts	$182,863	$227,835
Joint interest accounts	2,016	2,245
Income taxes receivable	2,441	3,612
Other accounts	-614	6,515
Accounts receivable, gross	186,706	240,207
Allowance for doubtful accounts	-1,425	-1,198
Accounts receivable, net	185,281	239,009
Inventories
Natural gas in storage	2,394	3,281
Tubular goods and well equipment	11,535	10,675
Other accounts	158	70
Inventory, net	14,087	14,026
Other assets
Deferred compensation plan	13,322	13,115
Debt issuance cost	16,082	17,349
Other accounts	184	65
Other assets	29,588	30,529
Accounts payable
Trade accounts	68,891	54,949
Natural gas purchases	2,164	2,407
Royalty and other owners	93,316	97,298
Accrued capital costs	130,782	222,426
Taxes other than income	20,464	16,806
Drilling advances	87	88
Other accounts	5,511	6,102
Accounts payable current	321,215	400,076
Accrued liabilities
Employee benefits	10,819	22,815
Taxes other than income	7,455	7,128
Interest payable	13,755	30,677
Other accounts	2,550	3,049
Accrued liabilities	34,579	63,669
Other liabilities
Deferred compensation plan	29,096	28,932
Other accounts	9,312	10,675
Other liabilities	$38,408	$39,607