Cimarex Energy (CIMXP) 10-Q 6 Aug 14 2014 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
	Jun. 30, 2014
Document and Entity Information	'
Entity Registrant Name	'CIMAREX ENERGY CO
Entity Central Index Key	'0001168054
Document Type	'10-Q
Document Period End Date	30-Jun-14
Amendment Flag	'false
Current Fiscal Year End Date	'--12-31
Entity Current Reporting Status	'Yes
Entity Filer Category	'Large Accelerated Filer
Entity Common Stock, Shares Outstanding	87,021,935
Document Fiscal Year Focus	'2014
Document Fiscal Period Focus	'Q2

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$128,555	$4,531
Receivables, net	449,456	367,754
Oil and gas well equipment and supplies	85,278	66,772
Deferred income taxes	13,725	16,854
Derivative instruments	'	4,268
Prepaid expenses	7,906	7,867
Other current assets	1,432	1,093
Total current assets	686,352	469,139
Oil and gas properties at cost, using the full cost method of accounting:	'	'
Proved properties	13,801,249	12,863,961
Unproved properties and properties under development, not being amortized	886,361	585,361
Gross oil and gas properties	14,687,610	13,449,322
Less - accumulated depreciation, depletion and amortization	-7,838,007	-7,483,685
Net oil and gas properties	6,849,603	5,965,637
Fixed assets, net	182,521	146,918
Goodwill	620,232	620,232
Other assets, net	60,299	51,209
Total assets	8,399,007	7,253,135
Current liabilities:	'	'
Accounts payable	126,259	116,110
Accrued liabilities	468,952	412,495
Derivative instruments	8,506	389
Revenue payable	197,473	154,173
Total current liabilities	801,190	683,167
Long-term debt	1,500,000	924,000
Deferred income taxes	1,626,206	1,459,841
Other liabilities	184,980	163,919
Total liabilities	4,112,376	3,230,927
Stockholders' equity:	'	'
Preferred stock, $0.01 par value, 15,000,000 shares authorized, no shares issued	'	'
Common stock, $0.01 par value, 200,000,000 shares authorized, 87,021,935 and 87,152,197 shares issued, respectively	870	872
Paid-in capital	1,975,159	1,970,113
Retained earnings	2,309,429	2,050,034
Accumulated other comprehensive income	1,173	1,189
Total stockholders' equity	4,286,631	4,022,208
Total liabilities and stockholders' equity	$8,399,007	$7,253,135

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Jun. 30, 2014	Dec. 31, 2013
Condensed Consolidated Balance Sheets	'	'
Preferred stock, par value (in dollars per share)	$0.01	$0.01
Preferred stock, shares authorized	15,000,000	15,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$0.01	$0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	87,021,935	87,152,197

Consolidated_Statements_of_Inc

Consolidated Statements of Income and Comprehensive Income (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Revenues:	'	'	'	'
Gas sales	$172,503	$126,547	$342,600	$227,668
Oil sales	354,882	304,466	679,953	561,998
NGL sales	95,470	52,309	185,427	109,184
Gas gathering and other	14,284	10,844	26,748	21,571
Gas marketing, net	-470	-409	1,157	-308
Total revenues	636,669	493,757	1,235,885	920,113
Costs and expenses:	'	'	'	'
Depreciation, depletion and amortization	194,989	147,231	368,920	283,669
Asset retirement obligation	3,650	2,884	6,868	5,283
Production	86,085	69,433	161,226	138,819
Transportation, processing and other operating	46,478	22,022	90,726	40,656
Gas gathering and other	10,041	5,184	18,825	11,340
Taxes other than income	32,323	27,807	65,944	52,935
General and administrative	16,571	22,836	37,283	38,413
Stock compensation	3,548	3,507	7,272	7,112
(Gain) loss on derivative instruments, net	2,454	-13,660	18,189	-12,057
Other operating, net	112	2,365	215	5,297
Total costs and expenses	396,251	289,609	775,468	571,467
Operating income	240,418	204,148	460,417	348,646
Other (income) and expense:	'	'	'	'
Interest expense	16,724	14,112	30,766	27,318
Capitalized interest	-8,575	-7,387	-15,865	-16,582
Other, net	-4,129	-8,758	-11,084	-11,374
Income before income tax	236,398	206,181	456,600	349,284
Income tax expense	87,758	76,616	169,503	129,792
Net income	148,640	129,565	287,097	219,492
Basic	'	'	'	'
Distributed (in dollars per share)	$0.16	$0.14	$0.32	$0.28
Undistributed (in dollars per share)	$1.55	$1.36	$2.98	$2.26
Total basic (in dollars per share)	$1.71	$1.50	$3.30	$2.54
Diluted	'	'	'	'
Distributed (in dollars per share)	$0.16	$0.14	$0.32	$0.28
Undistributed (in dollars per share)	$1.54	$1.35	$2.97	$2.25
Total diluted (in dollars per share)	$1.70	$1.49	$3.29	$2.53
Comprehensive income:	'	'	'	'
Net income	148,640	129,565	287,097	219,492
Other comprehensive income:	'	'	'	'
Change in fair value of investments, net of tax	-56	19	-16	99
Total comprehensive income	$148,584	$129,584	$287,081	$219,591

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Cash Flows (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Cash flows from operating activities:	'	'
Net income	$287,097	$219,492
Adjustments to reconcile net income to net cash provided by operating activities:	'	'
Depreciation, depletion and amortization	368,920	283,669
Asset retirement obligation	6,868	5,283
Deferred income taxes	169,503	129,792
Stock compensation	7,272	7,112
(Gain) loss on derivative instruments	18,189	-12,057
Settlements on derivative instruments	-5,804	1,765
Changes in non-current assets and liabilities	-2,436	5,790
Other, net	2,395	-2,116
Changes in operating assets and liabilities:	'	'
Receivables, net	-81,702	-55,060
Other current assets	-19,182	14,840
Accounts payable and accrued liabilities	18,649	-28,724
Net cash provided by operating activities	769,769	569,786
Cash flows from investing activities:	'	'
Oil and gas expenditures	-1,138,539	-776,138
Sales of oil and gas assets	1,123	14,407
Sales of other assets	251	31,157
Other expenditures	-51,401	-25,475
Net cash used by investing activities	-1,188,566	-756,049
Cash flows from financing activities:	'	'
Net bank debt borrowings	-174,000	142,000
Proceeds from other long-term debt	750,000	'
Financing costs incurred	-11,218	'
Dividends paid	-26,022	-22,448
Issuance of common stock and other	4,061	1,705
Net cash provided by financing activities	542,821	121,257
Net change in cash and cash equivalents	124,024	-65,006
Cash and cash equivalents at beginning of period	4,531	69,538
Cash and cash equivalents at end of period	$128,555	$4,532

Basis_of_Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2014
Basis of Presentation	'
Basis of Presentation	'
		1		Basis of Presentation
	The accompanying unaudited financial statements have been prepared by Cimarex Energy Co. (“Cimarex”, “we”, or “us”) pursuant to rules and regulations of the Securities and Exchange Commission (SEC).  Accordingly, certain disclosures required by accounting principles generally accepted in the United States and normally included in Annual Reports on Form 10-K have been omitted.  Although management believes that our disclosures in these interim financial statements are adequate, they should be read in conjunction with the financial statements, summary of significant accounting policies, and footnotes included in our 2013 Annual Report on Form 10-K.
	In the opinion of management, the accompanying financial statements reflect all adjustments necessary to present fairly our financial position, results of operations, and cash flows for the periods and as of the dates shown.  We have evaluated subsequent events through the date of this filing.
	Oil and Gas Properties
	We use the full cost method of accounting for our oil and gas operations.  Accounting rules require us to perform a quarterly ceiling test calculation to test our oil and gas properties for possible impairment.  The primary components impacting this calculation are commodity prices, reserve quantities added and produced, overall exploration and development costs, depletion expense, and tax effects.  If the net capitalized cost of our oil and gas properties subject to amortization (the carrying value) exceeds the ceiling limitation, the excess would be charged to expense.  The ceiling limitation is equal to the sum of the present value discounted at 10% of estimated future net cash flows from proved reserves, the cost of properties not being amortized, the lower of cost or estimated fair value of unproven properties included in the costs being amortized, and all related tax effects.
	At June 30, 2014, the calculated value of the ceiling limitation exceeded the carrying value of our oil and gas properties subject to the test, and no impairment was necessary.   However, a decline of 9% in the value of the ceiling limitation would have resulted in an impairment.  If pricing conditions decline, or if there is a negative impact on one or more of the other components of the calculation, we may incur a full cost ceiling impairment related to our oil and gas properties in future quarters.
	Oil, Gas and NGL sales
	Oil, gas and NGL sales are based on the sales method by which revenue is recognized on actual volumes sold to purchasers.  There is a ready market for our products and sales occur soon after production.  The determination to record and separately disclose NGL volumes is based on the location at which both title contractually transfers from Cimarex to a buyer and the associated volumes can be physically quantified.  For those NGL volumes that we have recorded and disclosed separately, contractual title of the volumes has passed from Cimarex to a buyer at a point where the NGL volumes have been physically separated from the production stream.  Should title contractually transfer before NGL volumes can be physically separated and quantified (typically at the wellhead), we do not report separate NGL volumes and the value of the NGLs are included in the reported value of the disclosed gas volumes.
	Under certain contracts, when NGLs are extracted from the gas stream, processors receive as compensation a portion of the sales value from both the residue gas and the NGLs as a processing fee and remit the contractual proceeds to us.  Prior to 2014,  revenue was recognized net of these processing fees for residue gas and NGLs sold under these contracts as allowed under EITF 00-10 Accounting for Shipping and Handling Fees and Costs.   Beginning in 2014, we believe that with the increase in NGL production and the impact of recent changes to these contracts, these processing costs will become more significant in the future.  Accordingly, we have changed our policy to record these processing costs with operating costs as allowed under EITF 00-10.  As a result, beginning in 2014, our realized prices for sales under these contracts reflect the value of 100% of the residue gas and NGLs yielded by processing, rather than the value associated with the contractual proceeds we received.  The related processing fees now are included in “transportation, processing and other” operating costs.  The effect of this change in the current quarter and six months ended was that total revenue was $12.2 million and $24.1 million, respectively, higher with an offsetting increase in total transportation, processing and other costs.  There was no impact on operating income.  Financial statements for periods prior to 2014 have not been reclassified to reflect this change in accounting treatment as it was impracticable to do so.
	Use of Estimates
	The more significant areas requiring the use of management’s estimates and judgments relate to the estimation of proved oil and gas reserves, the use of these oil and gas reserves in calculating depletion, depreciation, and amortization (DD&A), the use of the estimates of future net revenues in computing ceiling test limitations and estimates of future abandonment obligations used in recording asset retirement obligations, and the assessment of goodwill.  Estimates and judgments are also required in determining allowance for bad debt, impairments of undeveloped properties and other assets, purchase price allocation, valuation of deferred tax assets, fair value measurements, and commitments and contingencies.
	Accounts Receivable, Accounts Payable, and Accrued Liabilities
	The components of our receivable accounts, accounts payable, and accrued liabilities are shown below:
			June 30,		December 31,
	(in thousands)		2014		2013
	Receivables, net of allowance
	Trade		$	95,201	$	83,070
	Oil and gas sales			333,614		265,050
	Gas gathering, processing, and marketing			20,452		19,102
	Other			189		532
	Receivables, net		$	449,456	$	367,754
	Accounts payable
	Trade		$	84,567	$	80,918
	Gas gathering, processing, and marketing			41,692		35,192
	Accounts payable		$	126,259	$	116,110
	Accrued liabilities
	Exploration and development		$	251,663	$	173,298
	Taxes other than income			27,134		27,509
	Other			190,155		211,688
	Accrued liabilities		$	468,952	$	412,495
	Recently Issued Accounting Standards
	In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2014-09, Revenue from Contracts with Customers (Topic 606).  The new revenue 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.  The guidance in this update supersedes the revenue recognition requirements in Topic 605, Revenue Recognition,  and most industry-specific guidance throughout the Industry Topics of the Codification.  We must comply with this ASU beginning in fiscal year 2017 and early adoption is not permitted.  Entities can choose to apply the standard using either the full retrospective approach or a modified retrospective approach.    We are currently evaluating the impact of the provisions of Topic 606 and the effects of adoption cannot be determined at this time.

Derivative_InstrumentsHedging

Derivative Instruments/Hedging	6 Months Ended
	Jun. 30, 2014
Derivative Instruments/Hedging	'
Derivative Instruments/Hedging	'
	2.Derivative Instruments/Hedging
	We periodically enter into derivative instruments to mitigate a portion of our potential exposure to a decline in commodity prices and the corresponding negative impact on cash flow available for reinvestment.  While the use of these instruments limits the downside risk of adverse price changes, their use may also limit future revenues from favorable price changes.
	The following tables summarize our outstanding hedging contracts as of June 30, 2014:
	Oil Contracts
								Weighted Average Price					Fair Value
	Period	Type		Volume/Day		Index (1)		Floor			Ceiling		(in thousands)
	Jul 14 – Dec 14	Collars		12,000 Bbls		WTI		$	85.00		$	103.47	$	-5,974
	(1)  WTI refers to West Texas Intermediate price as quoted on the New York Mercantile Exchange.
	Gas Contracts
								Weighted Average Price					Fair Value
	Period	Type		Volume/Day		Index (1)		Floor			Ceiling		(in thousands)
	Jul 14 – Dec 14	Collars		80,000 MMBtu		PEPL		$	3.51		$	4.57	$	-969
	Jul 14 – Dec 14	Collars		60,000 MMBtu		Perm EP		$	3.62		$	4.50	$	-1,563
	(1)  PEPL refers to Panhandle Eastern Pipe Line, Tex/OK Mid-Continent Index as quoted in Platt’s Inside FERC.  Perm EP refers to El Paso Natural Gas Company, Permian Basin Index as quoted in Platt's Inside FERC.
	Under a collar agreement, we receive the difference between the published index price and a floor price if the index price is below the floor.  We pay the difference between the ceiling price and the index price if the index price is above the contracted ceiling price.  No amounts are paid or received if the index price is between the floor and ceiling prices.
	Depending on changes in oil and gas futures markets and management’s view of underlying supply and demand trends, we may increase or decrease our hedging positions.
	We have elected not to account for our derivatives as cash flow hedges.  Therefore, we recognize settlements and changes in the assets or liabilities relating to our open derivative contracts in earnings.  Cash settlements of our contracts are included in cash flows from operating activities in our statements of cash flows.
	The following table summarizes the net gains and (losses) from settlements and changes in fair value of our derivative contracts as presented in our accompanying financial statements.
		Three Months Ended						Six Months Ended
		June 30,						June 30,
	(in thousands)	2014			2013			2014					2013
	Gain (loss) on derivative instruments, net:
	Natural gas contracts	$	2,062		$	9,199		$		-9,820			$		9,199
	Oil contracts		-4,516			4,461				-8,369					2,858
	Gain (loss) on derivative instruments, net	$	-2,454		$	13,660		$		-18,189			$		12,057
	Gains (losses) from settlement of derivative instruments:
	Natural gas contracts	$	-37		$	—		$		-4,824			$		—
	Oil contracts		-980			1,039				-980					1,765
	Settlement gains (losses)	$	-1,017		$	1,039		$		-5,804			$		1,765
	Our derivative contracts are carried at their fair value on our balance sheet using Level 2 inputs.  We estimate the fair value with internal risk-adjusted discounted cash flow calculations.  Cash flows are based on published forward commodity price curves for the underlying commodity as of the date of the estimate.  For collars, we estimate the option value of the contract floors and ceilings using an option pricing model, which takes into account market volatility, market prices, and contract terms.
	The fair value of our derivative instruments in an asset position includes a measure of counterparty credit risk and the fair value of instruments in a liability position includes a measure of our own non-performance risk.  These credit risks are based on current published credit default swap rates.
	Due to the volatility of commodity prices, the estimated fair value of our derivative instruments is subject to fluctuation from period to period, which could result in significant differences between the current estimated fair value and the ultimate settlement price.
	Our derivative instruments are subject to enforceable master netting arrangements, which allow us to offset recognized asset and liability fair value amounts on contracts with the same counterparty.  Our policy is to not offset asset and liability positions in our accompanying balance sheets.
	The following table presents the amounts and classifications of our derivative assets and liabilities as of June 30, 2014 and December 31, 2013, as well as the potential effect of netting arrangements on contracts with the same counterparty.
	June 30, 2014:
	(in thousands)	Balance Sheet Location		Asset			Liability
	Oil contracts	Current liabilities — Derivative instruments		$	—		$	5,974
	Natural gas contracts	Current liabilities — Derivative instruments			—			2,532
	Total gross amounts presented in accompanying balance sheet				—			8,506
	Less: gross amounts not offset in the accompanying balance sheet				—			—
	Net amount:			$	—		$	8,506
	December 31, 2013:
	(in thousands)	Balance Sheet Location		Asset			Liability
	Oil contracts	Current assets — Derivative instruments		$	1,805		$	—
	Natural gas contracts	Current assets — Derivative instruments			2,463			—
	Oil contracts	Current liabilities — Derivative instruments			—			389
	Total gross amounts presented in accompanying balance sheet				4,268			389
	Less: gross amounts not offset in the accompanying balance sheet				-389			-389
	Net amount:			$	3,879		$	—
	We are exposed to financial risks associated with our derivative contracts from non-performance by our counterparties.  We have mitigated our exposure to any single counterparty by contracting with a number of financial institutions, each of which has a high credit rating and is a member of our bank credit facility.  Our member banks do not require us to post collateral for our hedge liability positions.  Because some of the member banks have discontinued hedging activities, in the future we may hedge with counterparties outside our bank group to obtain competitive terms and to spread counterparty risk.

Fair_Value_Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2014
Fair Value Measurements	'
Fair Value Measurements	'
	3.Fair Value Measurements
	Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price).  The FASB has established a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value.  This hierarchy consists of three broad levels.  Level 1 inputs are the highest priority and consist of unadjusted quoted prices in active markets for identical assets and liabilities.  Level 2 are inputs other than quoted prices that are observable for the asset or liability, either directly or indirectly.  Level 3 are unobservable inputs for an asset or liability.
	The following tables provide fair value measurement information for certain assets and liabilities as of June 30, 2014 and December 31, 2013:
	June 30, 2014:	Carrying		Fair
	(in thousands)	Amount		Value
	Financial Assets (Liabilities):
	5.875% Notes due 2022	$	-750,000	$	-832,500
	4.375% Notes due 2024	$	-750,000	$	-765,938
	Derivative instruments — liabilities	$	-8,506	$	-8,506
	December 31, 2013:	Carrying		Fair
	(in thousands)	Amount		Value
	Financial Assets (Liabilities):
	Bank debt	$	-174,000	$	-174,000
	5.875% Notes due 2022	$	-750,000	$	-799,988
	Derivative instruments — assets	$	4,268	$	4,268
	Derivative instruments — liabilities	$	-389	$	-389
	Assessing the significance of a particular input to the fair value measurement requires judgment, including the consideration of factors specific to the asset or liability.  The following methods and assumptions were used to estimate the fair value of the assets and liabilities in the table above.
	Debt (Level 1)
	The fair value of our bank debt at December 31, 2013 was estimated to approximate the carrying amount because the floating rate interest paid on such debt was set for periods of three months or less.
	The fair value for our 4.375% and 5.875% fixed rate notes was based on their last traded value before period end.
	Derivative Instruments (Level 2)
	The fair value of our derivative instruments was estimated using internal discounted cash flow calculations.  Cash flows are based on the stated contract prices and current and published forward commodity price curves, adjusted for volatility.  The cash flows are risk adjusted relative to non-performance for both our counterparties and our liability positions.  Please see Note 2 for further information on the fair value of our derivative instruments.
	Other Financial Instruments
	The carrying amounts of our cash, cash equivalents, accounts receivable, accounts payable, and accrued liabilities approximate fair value because of the short-term maturities and/or liquid nature of these assets and liabilities.
	Most of our accounts receivable balances are uncollateralized and result from transactions with other companies in the oil and gas industry.  Concentration of customers may impact our overall credit risk because our customers may be similarly affected by changes in economic or other conditions within the industry.
	We routinely assess the recoverability of all material accounts receivable to determine their collectability.  We accrue a reserve to the allowance for doubtful accounts when it is probable that a receivable will not be collected and the amount of the reserve may be reasonably estimated.  At June 30, 2014 and December 31, 2013, the allowance for doubtful accounts was $3.2 million and $6.0 million, respectively.

Capital_Stock

Capital Stock	6 Months Ended
	Jun. 30, 2014
Capital Stock	'
Capital Stock	'
	4.Capital Stock
	Authorized capital stock consists of 200 million shares of common stock and 15 million shares of preferred stock.  At June 30, 2014, there were no shares of preferred stock outstanding.  A summary of our common stock activity for the six months ended June 30, 2014 follows:
	(in thousands)
	Issued and outstanding as of December 31, 2013	87,152
	Issuance of restricted stock awards	14
	Common stock reacquired and retired	-117
	Restricted stock forfeited and retired	-101
	Option exercises, net of cancellations	74
	Issued and outstanding as of June 30, 2014	87,022
	Dividends
	In May 2014, the Board of Directors declared a cash dividend of $0.16 per share.  The dividend is payable on September 2, 2014 to stockholders of record on August 15, 2014.  Future dividend payments will depend on our level of earnings, financial requirements, and other factors considered relevant by the Board of Directors.

Stockbased_Compensation

Stock-based Compensation	6 Months Ended
	Jun. 30, 2014
Stock-based Compensation	'
Stock-based Compensation	'
	5.Stock-based Compensation
	In May 2014, our 2014 Equity Incentive Plan (the 2014 Plan) was approved by stockholders and our previous plan was terminated at that time.  Outstanding awards under the previous plan were not impacted.  The primary purposes of the 2014 Plan are to increase the number of shares available in connection with awards, provide flexibility in the types of available awards and design of awards, modify certain individual award limits and revise the performance measures for qualified performance-based awards.  The 2014 Plan provides for grants of stock options, stock appreciation rights, restricted stock, restricted stock units, performance shares, performance units, dividend equivalents and other stock-based awards.  A total of 6.6 million shares of common stock may be issued under the 2014 Plan, including shares available from the previous plan.
	We have recognized non-cash stock-based compensation cost as follows:
		Three Months Ended						Six Months Ended
		June 30,						June 30,
	(in thousands)	2014			2013			2014			2013
	Restricted stock	$	5,979		$	6,017		$	12,430		$	11,923
	Stock options		782			707			1,555			1,415
			6,761			6,724			13,985			13,338
	Less amounts capitalized to oil and gas properties		-3,213			-3,217			-6,713			-6,226
	Compensation expense	$	3,548		$	3,507		$	7,272		$	7,112
	Historical amounts may not be representative of future amounts as additional awards may be granted.
	Restricted Stock and Units
	During the six months ended June 30, 2014 and 2013, we granted 13,652 and 49,036 service-based stock awards at a weighted average grant-date fair value of $127.30 and $70.92, respectively.
	From time to time performance awards are granted to eligible executives and are subject to market condition-based vesting determined by our stock price performance relative to a defined peer group’s stock price performance.  After three years of continued service, an executive will be entitled to vest in 50% to 100% of the award.  In accordance with Internal Revenue Code Section 162(m), certain of the amounts awarded may not be deductible for tax purposes.  Service-based stock awards granted to other eligible employees and non-employee directors have vesting schedules of three to five years.
	Compensation cost for the performance stock awards is based on the grant-date fair value of the award utilizing a Monte Carlo simulation model.  Compensation cost for the service-based vesting restricted shares is based upon the grant-date market value of the award.  Such costs are recognized ratably over the applicable vesting period.
	The following table reflects the non-cash compensation cost related to our restricted stock:
		Three Months Ended						Six Months Ended
		June 30,						June 30,
	(in thousands)	2014			2013			2014			2013
	Performance stock awards	$	2,867		$	2,568		$	5,814		$	5,253
	Service-based stock awards		3,112			3,449			6,616			6,670
			5,979			6,017			12,430			11,923
	Less amounts capitalized to oil and gas properties		-2,891			-2,954			-6,071			-5,738
	Restricted stock compensation expense	$	3,088		$	3,063		$	6,359		$	6,185
	Unrecognized compensation cost related to unvested restricted shares at June 30, 2014 was $55.6 million, which we expect to recognize over a weighted average period of approximately 2.3 years.
	The following table provides information on restricted stock and unit activity as of June 30, 2014 and changes during the year.  A restricted unit held by an employee represents a right to an unrestricted share of common stock upon completion of defined vesting and holding periods.  A restricted unit held by a non-employee director represents an election to defer payment of director fees until the time specified by the director in his deferred compensation agreement.  The remaining outstanding restricted units shown below represent restricted units held by a non-employee director who has elected to defer payment of common stock represented by the units until termination of his service on the Board of Directors.
		Restricted		Restricted
		Stock		Units
	Outstanding as of January 1, 2014	1,863,834		8,838
	Vested	-287,047		N/A
	Converted to stock	N/A		—
	Granted	13,652		—
	Canceled	-100,568		—
	Outstanding as of June 30, 2014	1,489,871		8,838
	Vested included in outstanding	N/A		8,838
	Stock Options
	Options that have been granted under the 2014 plan and previous plans expire seven to ten years from the grant date and have service-based vesting schedules of three to five years.  The exercise price for an option under the 2014 plan is the closing price of our common stock as reported by the New York Stock Exchange on the date of grant. The previous plans provided that all grants have an exercise price of the average of the high and low prices of our common stock as reported by the New York Stock Exchange on the date of grant.  No options were granted during the first six months of 2014 and 2013.
	Compensation cost related to stock options is based on the grant-date fair value of the award, recognized ratably over the applicable vesting period.  We estimate the fair value using the Black-Scholes option-pricing model.  Expected volatilities are based on the historical volatility of our common stock.  We also use historical data to estimate the probability of option exercise, expected years until exercise and potential forfeitures.  We use U.S. Treasury bond rates in effect at the grant date for our risk-free interest rates.
	Non-cash compensation cost related to our stock options is reflected in the following table:
		Three Months Ended						Six Months Ended
		June 30,						June 30,
	(in thousands)	2014			2013			2014			2013
	Stock option awards	$	782		$	707		$	1,555		$	1,415
	Less amounts capitalized to oil and gas properties		-322			-263			-642			-488
	Stock option compensation expense	$	460		$	444		$	913		$	927
	As of June 30, 2014, there was $2.7 million of unrecognized compensation cost related to non-vested stock options.  We expect to recognize that cost pro rata over a weighted-average period of approximately 1.2 years.
	Information about outstanding stock options is summarized below:
				Weighted			Weighted			Aggregate
				Average			Average			Intrinsic
				Exercise			Remaining			Value
		Options		Price			Term			(in thousands)
	Outstanding as of January 1, 2014	531,016		$	59.78
	Exercised	-73,935		$	54.92
	Forfeited	-7,670		$	63.42
	Outstanding as of June 30, 2014	449,411		$	60.52		4.9	Years		$	36,989
	Exercisable as of June 30, 2014	114,067		$	50.82		4.0	Years		$	10,495
	The following table provides information regarding the options exercised:
		Six months ended
		June 30,
	(dollars in thousands)	2014			2013
	Number of options exercised		73,935			43,156
	Cash received from option exercises	$	4,061		$	1,705
Intrinsic value of options exercised	$	4,632		$	1,407
The following table provides information on non-vested stock option activity as of June 30, 2014 and changes during the year:
			Weighted			Weighted
			Average			Average
			Grant-Date			Exercise
	Options		Fair Value			Price
Non-vested as of January 1, 2014	343,014		$	21.64		$	63.81
Forfeited	-7,670		$	21.94		$	63.42
Non-vested as of June 30, 2014	335,344		$	21.63		$	63.82

Asset_Retirement_Obligations

Asset Retirement Obligations	6 Months Ended
	Jun. 30, 2014
Asset Retirement Obligations	'
Asset Retirement Obligations	'
	6.Asset Retirement Obligations
	We recognize the fair value of liabilities for retirement obligations associated with tangible long-lived assets in the period in which there is a legal obligation associated with the retirement of such assets and the amount can be reasonably estimated.  The associated asset retirement costs are capitalized as part of the carrying amount of the long-lived asset.  This liability includes costs related to the plugging and abandonment of wells, the removal of facilities and equipment, and site restorations.  Subsequent to initial measurement, the asset retirement liability is required to be accreted each period.  If the fair value of a recorded asset retirement obligation changes, a revision is recorded to both the asset retirement obligation and the asset retirement capitalized cost.  Capitalized costs are included as a component of the DD&A calculations.
	The following table reflects the components of the change in the carrying amount of the asset retirement obligation for the six months ended June 30, 2014:
	(in thousands)
	Asset retirement obligation at January 1, 2014	$	154,026
	Liabilities incurred		7,905
	Liability settlements and disposals		-7,302
	Accretion expense		3,756
	Revisions of estimated liabilities		8,210
	Asset retirement obligation at June 30, 2014		166,595
	Less current obligation		-15,176
	Long-term asset retirement obligation	$	151,419

LongTerm_Debt

Long-Term Debt	6 Months Ended
	Jun. 30, 2014
Long-Term Debt	'
Long-Term Debt	'
	7.Long-Term Debt
	Debt at June 30, 2014 and December 31, 2013 consisted of the following:
		June 30,		December 31,
	(in thousands)	2014		2013
	Bank debt	$	—	$	174,000
	5.875% Senior Notes due 2022		750,000		750,000
	4.375% Senior Notes due 2024		750,000		—
	Total long-term debt	$	1,500,000	$	924,000
	Bank Debt
	In May 2014, we amended our senior unsecured revolving credit facility (Credit Facility) to extend the maturity date two years to July 14, 2018 and lowered the margins applicable to loans and commitments.  The amendment also raised our borrowing base from $2.25 billion to $2.5 billion until the next regular annual redetermination date scheduled for April 15, 2015.  The borrowing base under the Credit Facility is determined at the discretion of the lenders based on the value of our proved reserves.  Our aggregate commitments remained unchanged at $1 billion.
	As of June 30, 2014, we had letters of credit outstanding under the Credit Facility of $2.5 million, leaving an unused borrowing availability of $997.5 million.
	At our option, borrowings under the Credit Facility, as amended in May 2014, may bear interest at either (a) LIBOR plus 1.5-2.25%, based on our leverage ratio, or (b) the higher of (i) a prime rate, (ii) the federal funds effective rate plus 0.50%, or (iii) adjusted one-month LIBOR plus 1.0% plus, in each case, an additional 0.5-1.25%, based on our leverage ratio.
	The Credit Facility also has financial covenants that include the maintenance of current assets (including unused bank commitments) to current liabilities of greater than 1.0.  We also must maintain a leverage ratio of total debt to earnings before interest expense, income taxes and non-cash items (such as depreciation, depletion and amortization expense, unrealized gains and losses on commodity derivatives, ceiling test write-downs, and goodwill impairments) of not more than 3.5.  Other covenants could limit our ability to incur additional indebtedness, pay dividends, repurchase our common stock, or sell assets.  As of June 30, 2014, we were in compliance with all of the financial and non-financial covenants.
	5.875% Notes due 2022
	In April 2012, we issued $750 million of 5.875% senior notes due May 1, 2022, with interest payable semiannually in May and November.  The notes were sold to the public at par.  The notes are governed by an indenture containing certain covenants, events of default and other restrictive provisions.  We may redeem the notes in whole or in part, at any time on or after May 1, 2017, at redemption prices of 102.938% of the principal amount as of May 1, 2017, declining to 100% on May 1, 2020 and thereafter.
	4.375% Notes due 2024
	In June 2014, we issued $750 million of 4.375% senior notes due June 1, 2024, with interest payable semiannually in June and December.  The notes were sold to the public at par.  The notes are governed by an indenture containing certain covenants, events of default and other restrictive provisions. At any time prior to March 1, 2024, we may redeem all or a part of the notes at a defined make-whole redemption price calculated at the time of redemption.  At any time on or after March 1, 2024, we may redeem all or part of the notes at a price equal to 100% of the principal amount.

Income_Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2014
Income Taxes	'
Income Taxes	'
	8.Income Taxes
	The components of our provision for income taxes are as follows:
		Three months ended				Six months ended
		June 30,				June 30,
	(in thousands)	2014		2013		2014		2013
	Current benefit	$	—	$	—	$	—	$	—
	Deferred taxes		87,758		76,616		169,503		129,792
		$	87,758	$	76,616	$	169,503	$	129,792
	At December 31, 2013, we had a U.S. net tax operating loss carryforward of approximately $605.4 million, which would expire in tax years 2031 through 2033.  We believe that the carryforward will be utilized before it expires.  The amount of U.S. net tax operating loss carryforward that will be recorded to equity when utilized to reduce taxes payable is $56.4 million.  We also had an alternative minimum tax credit carryforward of approximately $4.1 million.
	At June 30, 2014, we had no unrecognized tax benefits that would impact our effective tax rate and we have made no provisions for interest or penalties related to uncertain tax positions.  The tax years 2009-2012 remain open to examination by the Internal Revenue Service of the United States.  We file tax returns with various state taxing authorities, which remain open to examination for the 2009-2012 tax years.
	Our provision for income taxes differed from the U.S. statutory rate of 35% primarily due to state income taxes and non-deductible expenses. The effective income tax rates for the three and six months ended June 30, 2014 and June 30,  2013 were 37.1% and 37.2%, respectively.

Supplemental_Disclosure_of_Cas

Supplemental Disclosure of Cash Flow Information:	6 Months Ended
	Jun. 30, 2014
Supplemental Disclosure of Cash Flow Information:	'
Supplemental Disclosure of Cash Flow Information:	'
	9.Supplemental Disclosure of Cash Flow Information
		Three months ended				Six months ended
		June 30,				June 30,
	(in thousands)	2014		2013		2014		2013
	Cash paid during the period for:
	Interest expense (including capitalized amounts)	$	24,195	$	24,208	$	26,290	$	25,226
	Interest capitalized	$	12,469	$	14,603	$	13,557	$	15,312
	Income taxes	$	353	$	150	$	354	$	205
	Cash received for income taxes	$	133	$	222	$	342	$	237

Earnings_per_Share

Earnings per Share	6 Months Ended
	Jun. 30, 2014
Earnings per Share	'
Earnings per Share	'
	10.Earnings per Share
	The calculations of basic and diluted net earnings per common share under the two-class method are presented below:
		Three months ended				Six months ended
		June 30,				June 30,
	(in thousands, except per share data)	2014		2013		2014		2013
	Basic:
	Net income	$	148,640	$	129,565	$	287,097	$	219,492
	Participating securities’ share in earnings		-2,320		-2,131		-4,464		-3,543
	Net income applicable to common stockholders	$	146,320	$	127,434	$	282,633	$	215,949
	Diluted:
	Net income	$	148,640	$	129,565	$	287,097	$	219,492
	Participating securities’ share in earnings		-2,316		-2,128		-4,457		-3,539
	Net income applicable to common stockholders	$	146,324	$	127,437	$	282,640	$	215,953
	Shares:
	Basic shares outstanding		85,532		84,942		85,532		84,942
	Incremental shares from assumed exercise of stock options		157		112		147		101
	Fully diluted common stock		85,689		85,054		85,679		85,043
	Excluded (1)		—		100		1		156
	Earnings per share to common stockholders (2):
	Basic	$	1.71	$	1.50	$	3.30	$	2.54
	Diluted	$	1.70	$	1.49	$	3.29	$	2.53
	(1)  Inclusion of certain outstanding stock options would have an anti-dilutive effect
	(2)  Earnings per share are based on actual figures rather than the rounded figures presented.

Commitments_and_Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2014
Commitments and Contingencies	'
Commitments and Contingencies	'
	11.Commitments and Contingencies
	Commitments
	We have commitments of $192.0 million to finish drilling and completing wells in progress at June 30, 2014.  We also have various commitments for drilling rigs.  The total minimum expenditure commitments under these agreements are $53.6 million.
	In New Mexico and Texas, we are constructing gathering facilities and pipelines.  At June 30, 2014, we had commitments of $6.6 million relating to these construction projects.
	At June 30, 2014, we had firm sales contracts to deliver approximately 34.7 Bcf of natural gas over the next 12 months.  If this gas is not delivered, our financial commitment would be approximately $146.4 million.  This commitment will fluctuate due to price volatility and actual volumes delivered.  However, we believe no financial commitment will be due based on our current proved reserves and production levels from which we can fulfill these obligations.
	We have other various transportation and delivery commitments in the normal course of business, which approximate $2 million over the next four years.
	We have various commitments for office space and equipment under operating lease arrangements totaling $131.7 million for the next five years and beyond.
	All of the noted commitments were routine and were made in the ordinary course of our business.
	Litigation
	In the ordinary course of business, we have various litigation matters.  We assess the probability of estimable amounts related to litigation matters in accordance with guidance established by the FASB and adjust our accruals accordingly.  Though some of the related claims may be significant, we believe the resolution of them, individually or in the aggregate, would not have a material adverse effect on our financial condition or results of operations after consideration of current accruals.
	H.B. Krug, et al versus H&P
	In January 2009, the Tulsa County District Court issued a judgment totaling $119.6 million in the H.B. Krug, et al. v. Helmerich & Payne, Inc. (H&P) case.  This lawsuit originally was filed in 1998 and addressed H&P’s conduct pertaining to a 1989 take-or-pay settlement, along with potential drainage and other related issues.  Pursuant to the 2002 spin-off of H&P, Cimarex assumed the assets and liabilities of H&P’s exploration and production business, including this lawsuit.  For 2008, we recorded a litigation expense of $119.6 million plus additional post-judgment interest and costs after the trial court entered a final judgment for these amounts.
	On December 10, 2013, the Oklahoma Supreme Court reversed the trial court’s original judgment of $119.6 million and affirmed an alternative jury verdict for $3.65 million.  In light of the Oklahoma Supreme Court’s ruling, on December 31, 2013, we reduced previously recognized litigation expense and the associated long-term liability by $142.8 million.
	On March 14, 2014, after denying the Plaintiffs’ Petition for Rehearing, the Oklahoma Supreme Court remanded the matter back to the trial court.  On March 31, 2014, the trial court entered a final judgment for damages, post-judgment interest and a payment in lieu of bond. The following day Cimarex paid the Plaintiffs $15.8 million in satisfaction of these awards, which now are final and not appealable.
	On June 24, 2014, the trial court ruled that the Plaintiffs were not entitled to prejudgment interest but were entitled to an award of attorney’s fees and costs.  At a subsequent hearing the trial court will determine the amount of the attorney’s fees and costs owed to Plaintiffs.  The outcome of these remaining issues cannot be determined at this time and will be subject to an appeal.  Our current assessments and estimates likely will change in the future as a result of subsequent legal proceedings both in the trial court and on appeal.

Property_Acquisition_and_Sales

Property Acquisition and Sales	6 Months Ended
	Jun. 30, 2014
Property Acquisitions and Sales	'
Property Acquisitions and Sales	'
	12.Property Acquisitions and Sales
	The following acquisitions and sales were made in the ordinary course of business.
	During the first half of 2014, we had property acquisitions of $259 million, primarily in the Cana-Woodford shale play in Western Oklahoma. In order to acquire and sell oil and gas properties in a tax efficient manner, we periodically enter into like-kind exchange tax deferred transactions. Certain of these property acquisitions were structured to qualify as the first step of a reverse like-kind exchange.  We utilized an exchange accommodation titleholder, a type of variable interest entity, for which we are the primary beneficiary.  Accordingly, we have consolidated the oil and gas assets and reserves attributable to these properties.  During the same period of 2013, we had property acquisitions of $4.6 million.
	There were no significant property sales during the first half of 2014.  Subsequent to June 30, 2014, we sold interests in Kansas non-core oil and gas properties for net proceeds of approximately $136 million.  In the first half of 2013, we sold interests in non-core oil and gas properties for $38.9 million. During the second quarter of 2013, we also sold a 50% interest in our Culberson County, Texas Triple Crown gas gathering and processing system for approximately $31 million.

Basis_of_Presentation_Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2014
Basis of Presentation	'
Oil and Gas Properties	'
	Oil and Gas Properties
	We use the full cost method of accounting for our oil and gas operations.  Accounting rules require us to perform a quarterly ceiling test calculation to test our oil and gas properties for possible impairment.  The primary components impacting this calculation are commodity prices, reserve quantities added and produced, overall exploration and development costs, depletion expense, and tax effects.  If the net capitalized cost of our oil and gas properties subject to amortization (the carrying value) exceeds the ceiling limitation, the excess would be charged to expense.  The ceiling limitation is equal to the sum of the present value discounted at 10% of estimated future net cash flows from proved reserves, the cost of properties not being amortized, the lower of cost or estimated fair value of unproven properties included in the costs being amortized, and all related tax effects.
	At June 30, 2014, the calculated value of the ceiling limitation exceeded the carrying value of our oil and gas properties subject to the test, and no impairment was necessary.   However, a decline of 9% in the value of the ceiling limitation would have resulted in an impairment.  If pricing conditions decline, or if there is a negative impact on one or more of the other components of the calculation, we may incur a full cost ceiling impairment related to our oil and gas properties in future quarters.
Revenue Recognition	'
	Oil, Gas and NGL sales
	Oil, gas and NGL sales are based on the sales method by which revenue is recognized on actual volumes sold to purchasers.  There is a ready market for our products and sales occur soon after production.  The determination to record and separately disclose NGL volumes is based on the location at which both title contractually transfers from Cimarex to a buyer and the associated volumes can be physically quantified.  For those NGL volumes that we have recorded and disclosed separately, contractual title of the volumes has passed from Cimarex to a buyer at a point where the NGL volumes have been physically separated from the production stream.  Should title contractually transfer before NGL volumes can be physically separated and quantified (typically at the wellhead), we do not report separate NGL volumes and the value of the NGLs are included in the reported value of the disclosed gas volumes.
	Under certain contracts, when NGLs are extracted from the gas stream, processors receive as compensation a portion of the sales value from both the residue gas and the NGLs as a processing fee and remit the contractual proceeds to us.  Prior to 2014,  revenue was recognized net of these processing fees for residue gas and NGLs sold under these contracts as allowed under EITF 00-10 Accounting for Shipping and Handling Fees and Costs.   Beginning in 2014, we believe that with the increase in NGL production and the impact of recent changes to these contracts, these processing costs will become more significant in the future.  Accordingly, we have changed our policy to record these processing costs with operating costs as allowed under EITF 00-10.  As a result, beginning in 2014, our realized prices for sales under these contracts reflect the value of 100% of the residue gas and NGLs yielded by processing, rather than the value associated with the contractual proceeds we received.  The related processing fees now are included in “transportation, processing and other” operating costs.  The effect of this change in the current quarter and six months ended was that total revenue was $12.2 million and $24.1 million, respectively, higher with an offsetting increase in total transportation, processing and other costs.  There was no impact on operating income.  Financial statements for periods prior to 2014 have not been reclassified to reflect this change in accounting treatment as it was impracticable to do so.
Use of Estimates	'
	Use of Estimates
	The more significant areas requiring the use of management’s estimates and judgments relate to the estimation of proved oil and gas reserves, the use of these oil and gas reserves in calculating depletion, depreciation, and amortization (DD&A), the use of the estimates of future net revenues in computing ceiling test limitations and estimates of future abandonment obligations used in recording asset retirement obligations, and the assessment of goodwill.  Estimates and judgments are also required in determining allowance for bad debt, impairments of undeveloped properties and other assets, purchase price allocation, valuation of deferred tax assets, fair value measurements, and commitments and contingencies.

Basis_of_Presentation_Tables

Basis of Presentation (Tables)	6 Months Ended
	Jun. 30, 2014
Basis of Presentation	'
Schedule of components of receivable accounts, accounts payable, and accrued liabilities	'
		June 30,		December 31,
	(in thousands)	2014		2013
	Receivables, net of allowance
	Trade	$	95,201	$	83,070
	Oil and gas sales		333,614		265,050
	Gas gathering, processing, and marketing		20,452		19,102
	Other		189		532
	Receivables, net	$	449,456	$	367,754
	Accounts payable
	Trade	$	84,567	$	80,918
	Gas gathering, processing, and marketing		41,692		35,192
	Accounts payable	$	126,259	$	116,110
	Accrued liabilities
	Exploration and development	$	251,663	$	173,298
	Taxes other than income		27,134		27,509
	Other		190,155		211,688
	Accrued liabilities	$	468,952	$	412,495

Derivative_InstrumentsHedging_

Derivative Instruments/Hedging (Tables)	6 Months Ended
	Jun. 30, 2014
Derivative	'
Net gains and (losses) from settlements and changes in fair value of derivative contracts	'
		Three Months Ended						Six Months Ended
		June 30,						June 30,
	(in thousands)	2014			2013			2014					2013
	Gain (loss) on derivative instruments, net:
	Natural gas contracts	$	2,062		$	9,199		$		-9,820			$		9,199
	Oil contracts		-4,516			4,461				-8,369					2,858
	Gain (loss) on derivative instruments, net	$	-2,454		$	13,660		$		-18,189			$		12,057
	Gains (losses) from settlement of derivative instruments:
	Natural gas contracts	$	-37		$	—		$		-4,824			$		—
	Oil contracts		-980			1,039				-980					1,765
	Settlement gains (losses)	$	-1,017		$	1,039		$		-5,804			$		1,765
Schedule of amounts and classifications of entity's derivative assets and liabilities as well as the potential effect of netting arrangements on contracts with the same counterparty	'
	June 30, 2014:
	(in thousands)	Balance Sheet Location		Asset			Liability
	Oil contracts	Current liabilities — Derivative instruments		$	—		$	5,974
	Natural gas contracts	Current liabilities — Derivative instruments			—			2,532
	Total gross amounts presented in accompanying balance sheet				—			8,506
	Less: gross amounts not offset in the accompanying balance sheet				—			—
	Net amount:			$	—		$	8,506
	December 31, 2013:
	(in thousands)	Balance Sheet Location		Asset			Liability
	Oil contracts	Current assets — Derivative instruments		$	1,805		$	—
	Natural gas contracts	Current assets — Derivative instruments			2,463			—
	Oil contracts	Current liabilities — Derivative instruments			—			389
	Total gross amounts presented in accompanying balance sheet				4,268			389
	Less: gross amounts not offset in the accompanying balance sheet				-389			-389
	Net amount:			$	3,879		$	—
Derivative Oil Contract [Member]	'
Derivative	'
Outstanding hedging contracts relative to future production	'
								Weighted Average Price					Fair Value
	Period	Type		Volume/Day		Index (1)		Floor			Ceiling		(in thousands)
	Jul 14 – Dec 14	Collars		12,000 Bbls		WTI		$	85.00		$	103.47	$	-5,974
	(1)  WTI refers to West Texas Intermediate price as quoted on the New York Mercantile Exchange.
Derivative Gas Contract [Member]	'
Derivative	'
Outstanding hedging contracts relative to future production	'
								Weighted Average Price					Fair Value
	Period	Type		Volume/Day		Index (1)		Floor			Ceiling		(in thousands)
	Jul 14 – Dec 14	Collars		80,000 MMBtu		PEPL		$	3.51		$	4.57	$	-969
	Jul 14 – Dec 14	Collars		60,000 MMBtu		Perm EP		$	3.62		$	4.50	$	-1,563
	(1)  PEPL refers to Panhandle Eastern Pipe Line, Tex/OK Mid-Continent Index as quoted in Platt’s Inside FERC.  Perm EP refers to El Paso Natural Gas Company, Permian Basin Index as quoted in Platt's Inside FERC.

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2014
Fair Value Measurements	'
Fair value measurement information for certain assets and liabilities	'
	June 30, 2014:	Carrying		Fair
	(in thousands)	Amount		Value
	Financial Assets (Liabilities):
	5.875% Notes due 2022	$	-750,000	$	-832,500
	4.375% Notes due 2024	$	-750,000	$	-765,938
	Derivative instruments — liabilities	$	-8,506	$	-8,506
	December 31, 2013:	Carrying		Fair
	(in thousands)	Amount		Value
	Financial Assets (Liabilities):
	Bank debt	$	-174,000	$	-174,000
	5.875% Notes due 2022	$	-750,000	$	-799,988
	Derivative instruments — assets	$	4,268	$	4,268
	Derivative instruments — liabilities	$	-389	$	-389

Capital_Stock_Tables

Capital Stock (Tables)	6 Months Ended
	Jun. 30, 2014
Capital Stock	'
Common stock activity	'
	(in thousands)
	Issued and outstanding as of December 31, 2013	87,152
	Issuance of restricted stock awards	14
	Common stock reacquired and retired	-117
	Restricted stock forfeited and retired	-101
	Option exercises, net of cancellations	74
	Issued and outstanding as of June 30, 2014	87,022

Stockbased_Compensation_Tables

Stock-based Compensation (Tables)	6 Months Ended
	Jun. 30, 2014
Options, Restricted Stock and Unit Awards	'
Recognition of non-cash stock-based compensation cost	'
		Three Months Ended						Six Months Ended
		June 30,						June 30,
	(in thousands)	2014			2013			2014			2013
	Restricted stock	$	5,979		$	6,017		$	12,430		$	11,923
	Stock options		782			707			1,555			1,415
			6,761			6,724			13,985			13,338
	Less amounts capitalized to oil and gas properties		-3,213			-3,217			-6,713			-6,226
	Compensation expense	$	3,548		$	3,507		$	7,272		$	7,112
Restricted Stock And Units [Member]	'
Options, Restricted Stock and Unit Awards	'
Recognition of non-cash stock-based compensation cost	'
		Three Months Ended						Six Months Ended
		June 30,						June 30,
	(in thousands)	2014			2013			2014			2013
	Performance stock awards	$	2,867		$	2,568		$	5,814		$	5,253
	Service-based stock awards		3,112			3,449			6,616			6,670
			5,979			6,017			12,430			11,923
	Less amounts capitalized to oil and gas properties		-2,891			-2,954			-6,071			-5,738
	Restricted stock compensation expense	$	3,088		$	3,063		$	6,359		$	6,185
Restricted stock and unit activity	'
		Restricted		Restricted
		Stock		Units
	Outstanding as of January 1, 2014	1,863,834		8,838
	Vested	-287,047		N/A
	Converted to stock	N/A		—
	Granted	13,652		—
	Canceled	-100,568		—
	Outstanding as of June 30, 2014	1,489,871		8,838
	Vested included in outstanding	N/A		8,838
Employee Stock Option [Member]	'
Options, Restricted Stock and Unit Awards	'
Recognition of non-cash stock-based compensation cost	'
		Three Months Ended						Six Months Ended
		June 30,						June 30,
	(in thousands)	2014			2013			2014			2013
	Stock option awards	$	782		$	707		$	1,555		$	1,415
	Less amounts capitalized to oil and gas properties		-322			-263			-642			-488
	Stock option compensation expense	$	460		$	444		$	913		$	927
Outstanding stock options	'
				Weighted			Weighted			Aggregate
				Average			Average			Intrinsic
				Exercise			Remaining			Value
		Options		Price			Term			(in thousands)
	Outstanding as of January 1, 2014	531,016		$	59.78
	Exercised	-73,935		$	54.92
	Forfeited	-7,670		$	63.42
	Outstanding as of June 30, 2014	449,411		$	60.52		4.9	Years		$	36,989
	Exercisable as of June 30, 2014	114,067		$	50.82		4.0	Years		$	10,495
Summary of information regarding options exercised and grant-date fair value of options vested	'
		Six months ended
		June 30,
	(dollars in thousands)	2014			2013
	Number of options exercised		73,935			43,156
	Cash received from option exercises	$	4,061		$	1,705
	Intrinsic value of options exercised	$	4,632		$	1,407
Status of non-vested stock options	'
				Weighted			Weighted
				Average			Average
				Grant-Date			Exercise
		Options		Fair Value			Price
	Non-vested as of January 1, 2014	343,014		$	21.64		$	63.81
	Forfeited	-7,670		$	21.94		$	63.42
	Non-vested as of June 30, 2014	335,344		$	21.63		$	63.82

Asset_Retirement_Obligations_T

Asset Retirement Obligations (Tables)	6 Months Ended
	Jun. 30, 2014
Asset Retirement Obligations	'
Change in the carrying amount of the asset retirement obligation	'
	(in thousands)
	Asset retirement obligation at January 1, 2014	$	154,026
	Liabilities incurred		7,905
	Liability settlements and disposals		-7,302
	Accretion expense		3,756
	Revisions of estimated liabilities		8,210
	Asset retirement obligation at June 30, 2014		166,595
	Less current obligation		-15,176
	Long-term asset retirement obligation	$	151,419

LongTerm_Debt_Tables

Long-Term Debt (Tables)	6 Months Ended
	Jun. 30, 2014
Long-Term Debt	'
Summary of debt	'
		June 30,		December 31,
	(in thousands)	2014		2013
	Bank debt	$	—	$	174,000
	5.875% Senior Notes due 2022		750,000		750,000
	4.375% Senior Notes due 2024		750,000		—
	Total long-term debt	$	1,500,000	$	924,000

Income_Taxes_Tables

Income Taxes (Tables)	6 Months Ended
	Jun. 30, 2014
Income Taxes	'
Components of the provision for income taxes	'
		Three months ended				Six months ended
		June 30,				June 30,
	(in thousands)	2014		2013		2014		2013
	Current benefit	$	—	$	—	$	—	$	—
	Deferred taxes		87,758		76,616		169,503		129,792
		$	87,758	$	76,616	$	169,503	$	129,792

Supplemental_Disclosure_of_Cas1

Supplemental Disclosure of Cash Flow Information: (Tables)	6 Months Ended
	Jun. 30, 2014
Supplemental Disclosure of Cash Flow Information:	'
Supplemental Disclosure of Cash Flow Information	'
		Three months ended				Six months ended
		June 30,				June 30,
	(in thousands)	2014		2013		2014		2013
	Cash paid during the period for:
	Interest expense (including capitalized amounts)	$	24,195	$	24,208	$	26,290	$	25,226
	Interest capitalized	$	12,469	$	14,603	$	13,557	$	15,312
	Income taxes	$	353	$	150	$	354	$	205
	Cash received for income taxes	$	133	$	222	$	342	$	237

Earnings_per_Share_Tables

Earnings per Share (Tables)	6 Months Ended
	Jun. 30, 2014
Earnings per Share	'
Calculations of basic and diluted net earnings (loss) per common share under the two-class method	'
		Three months ended				Six months ended
		June 30,				June 30,
	(in thousands, except per share data)	2014		2013		2014		2013
	Basic:
	Net income	$	148,640	$	129,565	$	287,097	$	219,492
	Participating securities’ share in earnings		-2,320		-2,131		-4,464		-3,543
	Net income applicable to common stockholders	$	146,320	$	127,434	$	282,633	$	215,949
	Diluted:
	Net income	$	148,640	$	129,565	$	287,097	$	219,492
	Participating securities’ share in earnings		-2,316		-2,128		-4,457		-3,539
	Net income applicable to common stockholders	$	146,324	$	127,437	$	282,640	$	215,953
	Shares:
	Basic shares outstanding		85,532		84,942		85,532		84,942
	Incremental shares from assumed exercise of stock options		157		112		147		101
	Fully diluted common stock		85,689		85,054		85,679		85,043
	Excluded (1)		—		100		1		156
	Earnings per share to common stockholders (2):
	Basic	$	1.71	$	1.50	$	3.30	$	2.54
	Diluted	$	1.70	$	1.49	$	3.29	$	2.53
	(1)  Inclusion of certain outstanding stock options would have an anti-dilutive effect
	(2)  Earnings per share are based on actual figures rather than the rounded figures presented

Basis_of_Presentation_Details

Basis of Presentation (Details) (USD $)	3 Months Ended	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2014	Dec. 31, 2013
Oil and Gas Properties	'	'	'
Discount rate for calculating present value of estimated future net revenues from proved reserves (as a percent)	'	10.00%	'
Impairment of oil and gas properties	'	$0	'
Ceiling limitation used in ceiling test sensitivity analysis	'	9.00%	'
Oil, Gas and NGL Sales	'	'	'
Increase in total revenue and processing costs	12,200,000	24,100,000	'
Portion of residue gas and NGLs yielded by processing (as a percent)	'	100.00%	'
Receivables, net of allowance	'	'	'
Trade	95,201,000	95,201,000	83,070,000
Oil and gas sales	333,614,000	333,614,000	265,050,000
Gas gathering, processing, and marketing	20,452,000	20,452,000	19,102,000
Other	189,000	189,000	532,000
Receivables, net	449,456,000	449,456,000	367,754,000
Accounts payable	'	'	'
Trade	84,567,000	84,567,000	80,918,000
Gas gathering, processing, and marketing	41,692,000	41,692,000	35,192,000
Accounts payable	126,259,000	126,259,000	116,110,000
Accrued liabilities	'	'	'
Exploration and development	251,663,000	251,663,000	173,298,000
Taxes other than income	27,134,000	27,134,000	27,509,000
Other	190,155,000	190,155,000	211,688,000
Accrued liabilities	$468,952,000	$468,952,000	$412,495,000

Derivative_InstrumentsHedging_1

Derivative Instruments/Hedging (Details) (Period From April2014 To December2014 [Member], USD $)	Jun. 30, 2014
In Thousands, unless otherwise specified
Derivative Contract Oil Collar W T I Index [Member]	'
Fair values of derivative assets and liabilities	'
Contract amount in barrels per day	12,000
Fair value	($5,974)
Weighted Average Price	'
Floor, weighted average price (in dollars per unit)	85
Ceiling, weighted average price (in dollars per unit)	103.47
Derivative Contract Gas Collar P E P L Index [Member]	'
Fair values of derivative assets and liabilities	'
Fair value	-969
Contract amount in MMBtu's per day	80,000
Weighted Average Price	'
Floor, weighted average price (in dollars per unit)	3.51
Ceiling, weighted average price (in dollars per unit)	4.57
Derivative Contract Gas Collar Perm E P [Member]	'
Fair values of derivative assets and liabilities	'
Fair value	($1,563)
Contract amount in MMBtu's per day	60,000
Weighted Average Price	'
Floor, weighted average price (in dollars per unit)	3.62
Ceiling, weighted average price (in dollars per unit)	4.5

Derivative_InstrumentsHedging_2

Derivative Instruments/Hedging (Details 2) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Gain (loss) on derivative instruments, net	'	'	'	'
Gain (loss) on derivative instruments, net	($2,454)	$13,660	($18,189)	$12,057
Gains (losses) from settlement of derivative instruments:	'	'	'	'
Settlement gains (losses)	'	'	-5,804	1,765
Nondesignated [Member]	'	'	'	'
Gain (loss) on derivative instruments, net	'	'	'	'
Gain (loss) on derivative instruments, net	-2,454	13,660	-18,189	12,057
Gains (losses) from settlement of derivative instruments:	'	'	'	'
Settlement gains (losses)	-1,017	1,039	-5,804	1,765
Natural Gas Contracts [Member] | Nondesignated [Member]	'	'	'	'
Gain (loss) on derivative instruments, net	'	'	'	'
Gain (loss) on derivative instruments, net	2,062	9,199	-9,820	9,199
Gains (losses) from settlement of derivative instruments:	'	'	'	'
Settlement gains (losses)	-37	'	-4,824	'
Oil Contracts [Member] | Nondesignated [Member]	'	'	'	'
Gain (loss) on derivative instruments, net	'	'	'	'
Gain (loss) on derivative instruments, net	-4,516	4,461	-8,369	2,858
Gains (losses) from settlement of derivative instruments:	'	'	'	'
Settlement gains (losses)	($980)	$1,039	($980)	$1,765

Derivative_InstrumentsHedging_3

Derivative Instruments/Hedging (Details 3) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Liability	'	'
Total gross amounts presented in accompanying balance sheet	$8,506	$389
Nondesignated [Member]	'	'
Asset	'	'
Total gross amounts presented in accompanying balance sheet	'	4,268
Less: gross amounts not offset in the accompanying balance sheet	'	-389
Net amount:	'	3,879
Liability	'	'
Total gross amounts presented in accompanying balance sheet	8,506	389
Less: gross amounts not offset in the accompanying balance sheet	'	-389
Net amount:	8,506	'
Nondesignated [Member] | Oil Contracts [Member] | Other Current Assets [Member]	'	'
Asset	'	'
Total gross amounts presented in accompanying balance sheet	'	1,805
Nondesignated [Member] | Oil Contracts [Member] | Other Current Liabilities [Member]	'	'
Liability	'	'
Total gross amounts presented in accompanying balance sheet	5,974	389
Nondesignated [Member] | Natural Gas Contracts [Member] | Other Current Assets [Member]	'	'
Asset	'	'
Total gross amounts presented in accompanying balance sheet	'	2,463
Nondesignated [Member] | Natural Gas Contracts [Member] | Other Current Liabilities [Member]	'	'
Liability	'	'
Total gross amounts presented in accompanying balance sheet	$2,532	'

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013	Apr. 30, 2012
In Thousands, unless otherwise specified
Financial Assets (Liabilities):	'	'	'
Derivative instruments - liabilities	-8,506	-389	'
Notes 5.875 Percent [Member]	'	'	'
Financial Assets (Liabilities):	'	'	'
Interest rate (as a percent)	5.88%	5.88%	5.88%
Notes 5.875 Percent [Member] | Fair Value Inputs Level1 [Member]	'	'	'
Financial Assets (Liabilities):	'	'	'
Interest rate (as a percent)	5.88%	'	'
Notes 4.375 Percent [Member]	'	'	'
Financial Assets (Liabilities):	'	'	'
Interest rate (as a percent)	4.38%	'	'
Notes 4.375 Percent [Member] | Fair Value Inputs Level1 [Member]	'	'	'
Financial Assets (Liabilities):	'	'	'
Interest rate (as a percent)	4.38%	'	'
Carrying Reported Amount Fair Value Disclosure [Member]	'	'	'
Financial Assets (Liabilities):	'	'	'
Derivative instruments - assets	'	4,268	'
Derivative instruments - liabilities	-8,506	-389	'
Carrying Reported Amount Fair Value Disclosure [Member] | Notes 5.875 Percent [Member]	'	'	'
Financial Assets (Liabilities):	'	'	'
Long-term debt	-750,000	-750,000	'
Carrying Reported Amount Fair Value Disclosure [Member] | Line Of Credit [Member]	'	'	'
Financial Assets (Liabilities):	'	'	'
Long-term debt	'	-174,000	'
Carrying Reported Amount Fair Value Disclosure [Member] | Notes 4.375 Percent [Member]	'	'	'
Financial Assets (Liabilities):	'	'	'
Long-term debt	-750,000	'	'
Estimate Of Fair Value Fair Value Disclosure [Member]	'	'	'
Financial Assets (Liabilities):	'	'	'
Derivative instruments - assets	'	4,268	'
Derivative instruments - liabilities	-8,506	-389	'
Estimate Of Fair Value Fair Value Disclosure [Member] | Notes 5.875 Percent [Member]	'	'	'
Financial Assets (Liabilities):	'	'	'
Long-term debt	-832,500	-799,988	'
Estimate Of Fair Value Fair Value Disclosure [Member] | Line Of Credit [Member]	'	'	'
Financial Assets (Liabilities):	'	'	'
Long-term debt	'	-174,000	'
Estimate Of Fair Value Fair Value Disclosure [Member] | Notes 4.375 Percent [Member]	'	'	'
Financial Assets (Liabilities):	'	'	'
Long-term debt	-765,938	'	'

Fair_Value_Measurements_Detail1

Fair Value Measurements (Details 2) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2014	Dec. 31, 2013
		Allowance For Trade Receivables [Member]	Allowance For Trade Receivables [Member]
Other Financial Instruments	'	'	'
Aggregate allowance for doubtful accounts	'	$3.20	$6
Period for which floating interest rate is set (in months)	'3 months	'	'

Capital_Stock_Details

Capital Stock (Details) (USD $)	1 Months Ended	6 Months Ended
	31-May-14	Jun. 30, 2014	Dec. 31, 2013
Capital Stock	'	'	'
Common stock, shares authorized	'	200,000,000	200,000,000
Preferred stock, shares authorized	'	15,000,000	15,000,000
Preferred stock outstanding (in shares)	'	0	'
Summary of issued and outstanding common stock activity	'	'	'
Beginning balance, shares	'	87,152,197	'
Issuance of restricted stock awards, shares	'	14,000	'
Common stock reacquired and retired, shares	'	-117,000	'
Restricted stock forfeited and retired, shares	'	-101,000	'
Option exercises, net of cancellations	'	74,000	'
Ending balance, shares	'	87,021,935	'
Dividends	'	'	'
Cash dividend declared (in dollars per share)	$0.16	'	'

Stockbased_Compensation_Detail

Stock-based Compensation (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	31-May-14
Stock-based Compensation	'	'	'	'	'
Maximum number of shares of common stock that may be issued under the Stock Incentive Plan	'	'	'	'	6,600,000
Options, Restricted Stock and Unit Awards	'	'	'	'	'
Compensation expense before capitalized cost	$6,761,000	$6,724,000	$13,985,000	$13,338,000	'
Less amounts capitalized to oil and gas properties	-3,213,000	-3,217,000	-6,713,000	-6,226,000	'
Compensation expense	3,548,000	3,507,000	7,272,000	7,112,000	'
Restricted Stock And Units [Member]	'	'	'	'	'
Options, Restricted Stock and Unit Awards	'	'	'	'	'
Unrecognized compensation costs related to unvested awards (in dollars)	55,600,000	'	55,600,000	'	'
Expected period to recognize unamortized compensation costs related to unvested awards	'	'	'2 years 3 months 18 days	'	'
Restricted Stock [Member]	'	'	'	'	'
Options, Restricted Stock and Unit Awards	'	'	'	'	'
Compensation expense before capitalized cost	5,979,000	6,017,000	12,430,000	11,923,000	'
Less amounts capitalized to oil and gas properties	-2,891,000	-2,954,000	-6,071,000	-5,738,000	'
Compensation expense	3,088,000	3,063,000	6,359,000	6,185,000	'
Restricted stock granted (in shares)	'	'	13,652	'	'
Performance Based Restricted Stock [Member]	'	'	'	'	'
Options, Restricted Stock and Unit Awards	'	'	'	'	'
Compensation expense before capitalized cost	2,867,000	2,568,000	5,814,000	5,253,000	'
Minimum years of continued service before restricted shares issued to certain executives vest	'	'	'3 years	'	'
Performance Based Restricted Stock [Member] | Maximum [Member]	'	'	'	'	'
Options, Restricted Stock and Unit Awards	'	'	'	'	'
Award vesting percentage	'	'	100.00%	'	'
Performance Based Restricted Stock [Member] | Minimum [Member]	'	'	'	'	'
Options, Restricted Stock and Unit Awards	'	'	'	'	'
Award vesting percentage	'	'	50.00%	'	'
Service Based Restricted Stock [Member]	'	'	'	'	'
Options, Restricted Stock and Unit Awards	'	'	'	'	'
Compensation expense before capitalized cost	3,112,000	3,449,000	6,616,000	6,670,000	'
Restricted stock granted (in shares)	'	'	13,652	49,036	'
Restricted stock granted, weighted average grant-date fair value (in dollars per share)	'	'	$127.30	$70.92	'
Service Based Restricted Stock [Member] | Maximum [Member]	'	'	'	'	'
Options, Restricted Stock and Unit Awards	'	'	'	'	'
Vesting period	'	'	'5 years	'	'
Service Based Restricted Stock [Member] | Minimum [Member]	'	'	'	'	'
Options, Restricted Stock and Unit Awards	'	'	'	'	'
Vesting period	'	'	'3 years	'	'
Employee Stock Option [Member]	'	'	'	'	'
Options, Restricted Stock and Unit Awards	'	'	'	'	'
Compensation expense before capitalized cost	782,000	707,000	1,555,000	1,415,000	'
Less amounts capitalized to oil and gas properties	-322,000	-263,000	-642,000	-488,000	'
Compensation expense	460,000	444,000	913,000	927,000	'
Unrecognized compensation costs related to unvested awards (in dollars)	$2,700,000	'	$2,700,000	'	'
Expected period to recognize unamortized compensation costs related to unvested awards	'	'	'1 year 2 months 12 days	'	'
Employee Stock Option [Member] | Maximum [Member]	'	'	'	'	'
Options, Restricted Stock and Unit Awards	'	'	'	'	'
Vesting period	'	'	'5 years	'	'
Employee Stock Option [Member] | Minimum [Member]	'	'	'	'	'
Options, Restricted Stock and Unit Awards	'	'	'	'	'
Vesting period	'	'	'3 years	'	'

Stockbased_Compensation_Detail1

Stock-based Compensation (Details 2)	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2014	Dec. 31, 2013
	Restricted Stock [Member]	Restricted Stock Units R S U [Member]	Restricted Stock Units R S U [Member]
Restricted stock and unit activity	'	'	'
Outstanding at the beginning of the period (in shares)	1,863,834	8,838	8,838
Vested (in shares)	-287,047	'	'
Granted (in shares)	13,652	'	'
Canceled (in shares)	-100,568	'	'
Outstanding at the end of the period (in shares)	1,489,871	8,838	8,838
Vested included in outstanding (in shares)	'	8,838	'

Stockbased_Compensation_Detail2

Stock-based Compensation (Details 3) (Employee Stock Option [Member], USD $)	6 Months Ended
In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Outstanding Stock Options	'	'
Outstanding balance at beginning of period (in shares)	531,016	'
Granted (in shares)	0	0
Exercised (in shares)	-73,935	-43,156
Forfeited (in shares)	-7,670	'
Outstanding balance at end of period (in shares)	449,411	'
Exercisable at end of period (in shares)	114,067	'
Weighted Average Exercise Price	'	'
Outstanding balance at beginning of period (in dollars per share)	$59.78	'
Exercised (in dollars per share)	$54.92	'
Forfeited (in dollars per share)	$63.42	'
Outstanding at end of period (in dollars per share)	$60.52	'
Exercisable at end of period (in dollars per share)	$50.82	'
Weighted Average Remaining Term	'	'
Weighted Average Remaining Term, Outstanding at end of period	'4 years 10 months 24 days	'
Weighted Average Remaining Term, Exercisable at end of period	'4 years	'
Aggregate Intrinsic Value	'	'
Aggregate Intrinsic Value Outstanding at end of period (in dollars)	$36,989	'
Aggregate Intrinsic Value Exercisable at the end of the period (in dollars)	10,495	'
Grant-Date Fair value	'	'
Number of options exercised (in shares)	73,935	43,156
Cash received from option exercises	4,061	1,705
Intrinsic value of stock options exercised	$4,632	$1,407
Non-vested Stock Options	'	'
Non-vested at the beginning of the period (in shares)	343,014	'
Granted (in shares)	0	0
Forfeited (in shares)	-7,670	'
Non-vested at the end of the period (in shares)	335,344	'
Weighted Average Grant Date Fair Value - Non-Vested Stock Options	'	'
Non-vested at the beginning of the period (in dollars per share)	$21.64	'
Forfeited (in dollars per share)	$21.94	'
Non-vested at the end of the period (in dollars per share)	$21.63	'
Weighted Average Exercise Price - Non-Vested Stock Options	'	'
Non-vested at the beginning of the period (in dollars per share)	$63.81	'
Forfeited (in dollars per share)	$63.42	'
Non-vested at the end of the period (in dollars per share)	$63.82	'
Maximum [Member]	'	'
Grant-Date Fair value	'	'
Vesting period	'5 years	'
Term of options from grant to expiration	'10 years	'
Minimum [Member]	'	'
Grant-Date Fair value	'	'
Vesting period	'3 years	'
Term of options from grant to expiration	'7 years	'

Asset_Retirement_Obligations_D

Asset Retirement Obligations (Details) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014
Asset Retirement Obligations	'
Balance at beginning of year	$154,026
Liabilities incurred	7,905
Liability settlements and disposals	-7,302
Accretion expense	3,756
Revisions of estimated liabilities	8,210
Balance at end of year	166,595
Less current obligation	-15,176
Long-term asset retirement obligation	$151,419

LongTerm_Debt_Details

Long-Term Debt (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013	Apr. 30, 2012
In Thousands, unless otherwise specified
Debt Instrument	'	'	'
Long-term debt	$1,500,000	$924,000	'
Notes 4.375 Percent [Member]	'	'	'
Debt Instrument	'	'	'
Long-term debt	750,000	'	'
Interest rate (as a percent)	4.38%	'	'
Line Of Credit [Member]	'	'	'
Debt Instrument	'	'	'
Long-term debt	'	174,000	'
Notes 5.875 Percent [Member]	'	'	'
Debt Instrument	'	'	'
Long-term debt	$750,000	$750,000	$750,000
Interest rate (as a percent)	5.88%	5.88%	5.88%

LongTerm_Debt_Details_2

Long-Term Debt (Details 2) (USD $)

Jun. 30, 2014

Dec. 31, 2013

31-May-14

Jun. 30, 2014

Apr. 30, 2014

Dec. 31, 2013

Jun. 30, 2014

Jun. 30, 2014

Dec. 31, 2013

Apr. 30, 2012

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Jun. 30, 2014

Line Of Credit [Member]

Line Of Credit [Member]

Line Of Credit [Member]

Line Of Credit [Member]

Line Of Credit [Member]

Notes 5.875 Percent [Member]

Notes 5.875 Percent [Member]

Notes 5.875 Percent [Member]

Notes 4.375 Percent [Member]

London Interbank Offered Rate L I B O R [Member]

London Interbank Offered Rate L I B O R [Member]

London Interbank Offered Rate L I B O R [Member]

Debt Instrument Variable Rate Federal Funds [Member]

Debt Instrument Variable Rate Federal Funds [Member]

Debt Instrument Variable Rate Base One Month Adjusted L I B O R [Member]

Debt Instrument Variable Rate Base One Month Adjusted L I B O R [Member]

Minimum [Member]

Line Of Credit [Member]

Line Of Credit [Member]

Line Of Credit [Member]

Line Of Credit [Member]

Line Of Credit [Member]

Minimum [Member]

Maximum [Member]

Debt Instrument

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Period of maturity date extension

'

'

'2 years

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Borrowing base of credit facility

'

'

$2,500,000,000

'

$2,250,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Bank commitments of credit facility

'

'

'

1,000,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Long-term debt

1,500,000,000

924,000,000

'

'

'

174,000,000

'

750,000,000

750,000,000

750,000,000

750,000,000

'

'

'

'

'

'

'

Letters of credit outstanding under the credit facility

'

'

'

2,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Unused borrowing availability

'

'

'

$997,500,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Variable rate basis

'

'

'

'

'

'

'

'

'

'

'

'LIBOR

'

'

'federal funds effective rate

'

'adjusted one-month LIBOR

'

Interest rate margin (as a percent)

'

'

'

'

'

'

'

'

'

'

'

'

1.50%

2.25%

'

0.50%

'

1.00%

Additional interest rate margin, low end of range (as a percent)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

0.50%

'

0.50%

Additional interest rate margin, high end of range (as a percent)

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

1.25%

'

1.25%

Current ratio to be maintained under credit facility

'

'

'

'

'

'

1

'

'

'

'

'

'

'

'

'

'

'

Maximum leverage ratio

'

'

'

3.5

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Interest rate (as a percent)

'

'

'

'

'

'

'

5.88%

5.88%

5.88%

4.38%

'

'

'

'

'

'

'

Redemption price during first period (as a percent)

'

'

'

'

'

'

'

'

'

102.938

'

'

'

'

'

'

'

'

Redemption price after first period (as a percent)

'

'

'

'

'

'

'

'

'

100

100

'

'

'

'

'

'

'

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Components of provision for income taxes (in thousands):	'	'	'	'	'
Deferred taxes	$87,758,000	$76,616,000	$169,503,000	$129,792,000	'
Total income tax expense (benefits)	87,758,000	76,616,000	169,503,000	129,792,000	'
U.S. net tax operating loss carryforward	'	'	'	'	605,400,000
U.S. net tax operating loss carryforward recorded to equity when utilized to reduce taxes payable	'	'	'	'	56,400,000
Alternative minimum tax credit carryforward	'	'	'	'	4,100,000
Unrecognized tax benefits that would impact the entity's effective rate	0	'	0	'	'
Provisions for interest or penalties related to uncertain tax positions	$0	'	$0	'	'
U.S. statutory rate (as a percent)	'	'	35.00%	'	'
Effective income tax rates (as a percent)	37.10%	37.20%	37.10%	37.20%	'

Supplemental_Disclosure_of_Cas2

Supplemental Disclosure of Cash Flow Information: (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Cash paid during the period for:	'	'	'	'
Interest expense (including capitalized amounts)	$24,195	$24,208	$26,290	$25,226
Interest capitalized	12,469	14,603	13,557	15,312
Income taxes	353	150	354	205
Cash received for income taxes	$133	$222	$342	$237

Earnings_per_Share_Details

Earnings per Share (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Basic:	'	'	'	'
Net income	$148,640	$129,565	$287,097	$219,492
Participating securities' share in earnings (in dollars)	-2,320	-2,131	-4,464	-3,543
Net income applicable to common shareholders	146,320	127,434	282,633	215,949
Diluted:	'	'	'	'
Net income	148,640	129,565	287,097	219,492
Participating securities' share in earnings (in dollars)	-2,316	-2,128	-4,457	-3,539
Net income applicable to common shareholders	$146,324	$127,437	$282,640	$215,953
Shares:	'	'	'	'
Basic shares outstanding	85,532	84,942	85,532	84,942
Incremental shares from assumed exercise of stock options	157	112	147	101
Fully diluted common stock (in shares)	85,689	85,054	85,679	85,043
Excluded antidilutive securities (in shares)	'	100	1	156
Earnings per share to common shareholders	'	'	'	'
Basic (in dollars per share)	$1.71	$1.50	$3.30	$2.54
Diluted (in dollars per share)	$1.70	$1.49	$3.29	$2.53

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014
Drilling Commitments [Member]	'
Construction, Drilling and Purchase Commitments	'
Commitments for purchases and other expenditures	$192
Gathering Facilities And Pipelines Commitments [Member]	'
Construction, Drilling and Purchase Commitments	'
Commitments for purchases and other expenditures	6.6
Commitments To Secure Use Of Drilling Rigs [Member]	'
Construction, Drilling and Purchase Commitments	'
Commitments for purchases and other expenditures	$53.60

Commitments_and_Contingencies_1

Commitments and Contingencies (Details 2) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014
Non-cancelable operating leases	'
Future minimum operating lease arrangements	$131.70
Natural Gas Sales Contracts [Member]	'
Delivery Commitments	'
Volume of gas deliverable (in Bcf)	34,700
Delivery term	'12 months
Financial commitment upon nondelivery	146.4
Other Transportation And Delivery Commitments [Member]	'
Delivery Commitments	'
Delivery term	'4 years
Financial commitment upon nondelivery	$2

Commitments_and_Contingencies_2

Commitments and Contingencies (Details 3) (Helmerich And Payne Case [Member], USD $)	0 Months Ended		1 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Apr. 01, 2014	Dec. 10, 2013	Jan. 31, 2009	Dec. 31, 2013	Dec. 31, 2008
Helmerich And Payne Case [Member]	'	'	'	'	'
Loss Contingencies	'	'	'	'	'
Accrued litigation expense	'	'	'	'	$119.60
Award to plaintiff, damages and disgorgement	'	'	119.6	'	'
Reversal of initial award to plaintiff, disgorgement	'	119.6	'	'	'
Loss Contingency, Damages Awarded, Value	'	3.65	'	'	'
Reduction in previously recognized litigation expense and associated long-term liability	'	'	'	142.8	'
Payments to plaintiff	$15.80	'	'	'	'

Property_Acquisitions_and_Sale

Property Acquisitions and Sales (Details) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Property Acquisitions and Sales	'	'
Acquisition of interest in oil and gas properties	'	$4.60
Property acquisitions	$259	'

Property_Acquisitions_and_Sale1

Property Acquisitions and Sales (Details 2) (USD $)	6 Months Ended		3 Months Ended	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2013	Jun. 30, 2013	Jun. 30, 2014
			Triple Crown Gas Gathering And Processing System [Member]	Non Core Oil And Gas Properties [Member]	Non Core Oil And Gas Properties [Member]
					Subsequent Event [Member]
Property Sales	'	'	'	'	'
Sale of interests in oil and gas properties	'	'	'	$38,900,000	$136,000,000
Sales of other assets	$251,000	$31,157,000	$31,000,000	'	'
Interest sold in property (as a percent)	'	'	50.00%	'	'