Cimarex Energy (CIMXP) 10-K 25 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Dec. 31, 2014	Feb. 13, 2015	Jun. 30, 2014
Document and Entity Information
Entity Registrant Name	CIMAREX ENERGY CO
Entity Central Index Key	1168054
Document Type	10-K
Document Period End Date	31-Dec-14
Amendment Flag	FALSE
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$12.30
Entity Common Stock, Shares Outstanding		87,597,134
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$405,862	$4,531
Accounts receivable:
Trade, net of allowance	134,443	83,070
Oil and gas sales, net of allowance	259,220	265,050
Gas gathering, processing, and marketing, net of allowance	18,009	19,102
Other	436	532
Oil and gas well equipment and supplies	89,780	66,772
Deferred income taxes	13,475	16,854
Derivative instruments		4,268
Prepaid expenses	9,356	7,867
Other current assets	1,223	1,093
Total current assets	931,804	469,139
Oil and gas properties at cost, using the full cost method of accounting:
Proved properties	14,402,064	12,863,961
Unproved properties and properties under development, not being amortized	759,149	585,361
Gross oil and gas properties	15,161,213	13,449,322
Less - accumulated depreciation, depletion and amortization	-8,257,502	-7,483,685
Net oil and gas properties	6,903,711	5,965,637
Fixed assets, less accumulated depreciation of $175,453 and $167,675	211,031	146,918
Goodwill	620,232	620,232
Other assets, net	58,515	51,209
Total assets	8,725,293	7,253,135
Accounts payable:
Trade	102,276	80,918
Gas gathering, processing, and marketing	35,775	35,192
Exploration and development	200,929	173,298
Taxes other than income	26,950	27,509
Other	219,505	211,688
Derivative instruments		389
Revenue payable	190,892	154,173
Total current liabilities	776,327	683,167
Long-term debt	1,500,000	924,000
Deferred income taxes	1,754,706	1,459,841
Asset retirement obligation	159,792	126,968
Other liabilities	33,836	36,951
Total liabilities	4,224,661	3,230,927
Stockholders' equity:
Common stock, $0.01 par value, 200,000,000 shares authorized, 87,592,535 and 87,152,197 shares issued, respectively	876	872
Paid-in capital	1,997,080	1,970,113
Retained earnings	2,501,574	2,050,034
Accumulated other comprehensive income	1,102	1,189
Total stockholders' equity	4,500,632	4,022,208
Total liabilities and stockholders' equity	$8,725,293	$7,253,135

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Condensed Consolidated Balance Sheets
Fixed assets, accumulated depreciation (in dollars)	$175,453	$167,675
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	87,592,535	87,152,197

CONSOLIDATED_STATEMENTS_OF_INC

CONSOLIDATED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues:
Oil sales	$1,308,958	$1,250,212	$1,027,757
Gas sales	687,930	471,045	340,744
NGL sales	375,941	231,248	213,149
Gas gathering and other	49,602	45,441	43,042
Gas marketing, net of related costs of $256,836, $187,772 and $86,813 respectively	1,745	105	-754
Total revenues	2,424,176	1,998,051	1,623,938
Costs and expenses:
Depreciation, depletion and amortization	806,021	615,874	513,916
Asset retirement obligation	10,082	7,989	13,019
Production	342,304	286,742	258,584
Transportation, processing and other operating	195,414	93,580	57,354
Gas gathering and other	35,113	25,876	21,965
Taxes other than income	128,793	112,732	86,994
General and administrative	81,160	77,466	54,428
Stock compensation	15,001	14,279	21,919
(Gain) loss on derivative instruments, net	-3,762	209	-245
Other operating (income) expense, net	116	-132,334	24,961
Total costs and expenses	1,610,242	1,102,413	1,052,895
Operating income	813,934	895,638	571,043
Other (income) and expense:
Interest expense	72,865	54,973	49,317
Capitalized interest	-35,925	-31,517	-35,174
Loss on early extinguishment of debt			16,214
Other, net	-28,907	-21,518	-19,864
Income before income tax	805,901	893,700	560,550
Income tax expense	298,697	329,011	206,727
Net income	507,204	564,689	353,823
Basic
Distributed (in dollars per share)	$0.64	$0.56	$0.48
Undistributed (in dollars per share)	$5.15	$5.92	$3.60
Total basic (in dollars per share)	$5.79	$6.48	$4.08
Diluted
Distributed (in dollars per share)	$0.64	$0.56	$0.48
Undistributed (in dollars per share)	$5.14	$5.91	$3.59
Total diluted (in dollars per share)	$5.78	$6.47	$4.07
Comprehensive income:
Net income	507,204	564,689	353,823
Other comprehensive income:
Change in fair value of investments, net of tax	-87	715	488
Total comprehensive income	$507,117	$565,404	$354,311

CONSOLIDATED_STATEMENTS_OF_INC1

CONSOLIDATED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME (Parenthetical) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Consolidated Statements of Income and Comprehensive Income
Gas marketing, related costs	$256,836	$187,772	$86,813

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net income	$507,204	$564,689	$353,823
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	806,021	615,874	513,916
Asset retirement obligation	10,082	7,989	13,019
Deferred income taxes	298,293	329,700	208,216
Stock compensation	15,001	14,279	21,919
(Gain) loss on derivative instruments	-3,762	209	-245
Settlements on derivative instruments	7,641	-4,088
Loss on early extinguishment of debt			16,214
Changes in non-current assets and liabilities	-2,440	-141,215	3,125
Other, net	-3,828	751	4,728
Changes in operating assets and liabilities:
Receivables, net	-35,133	-64,780	56,435
Other current assets	-25,428	14,234	4,209
Accounts payable and accrued liabilities	45,714	-13,294	-2,595
Net cash provided by operating activities	1,619,365	1,324,348	1,192,764
Cash flows from investing activities:
Oil and gas expenditures	-2,108,250	-1,572,288	-1,662,707
Sales of oil and gas assets	449,981	61,503	311,562
Sales of other assets	8,413	31,661	1,060
Other expenditures	-90,611	-51,913	-64,987
Net cash used by investing activities	-1,740,467	-1,531,037	-1,415,072
Cash flows from financing activities:
Net bank debt borrowings	-174,000	174,000	-55,000
Proceeds from other long-term debt	750,000		750,000
Other long-term debt payments			-363,595
Financing costs incurred	-11,616	-100	-13,821
Dividends paid	-53,849	-46,712	-39,577
Issuance of common stock and other	11,898	14,494	11,433
Net cash provided by financing activities	522,433	141,682	289,440
Net change in cash and cash equivalents	401,331	-65,007	67,132
Cash and cash equivalents at beginning of period	4,531	69,538	2,406
Cash and cash equivalents at end of period	$405,862	$4,531	$69,538

CONSOLIDATED_STATEMENTS_OF_STO

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $)	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
In Thousands, except Share data, unless otherwise specified
Balance at Dec. 31, 2011	$858	$1,908,506	$1,221,263	($14)	$3,130,613
Balance, shares at Dec. 31, 2011	85,774
Increase (Decrease) in Stockholders' Equity
Dividends			-41,318		-41,318
Net income			353,823		353,823
Unrealized change in fair value of investments, net of tax				488	488
Issuance of restricted stock awards	5	-5
Issuance of restricted stock awards, shares	562
Common stock reacquired and retired	-2	-11,015			-11,017
Common stock reacquired and retired, shares	-184
Restricted stock forfeited and retired	-1	1
Restricted stock forfeited and retired, shares	-141
Exercise of stock options	6	11,427			11,433
Exercise of stock options, shares	559
Vesting of restricted stock units, shares	26
Stock-based compensation		34,085			34,085
Stock-based compensation tax benefit		-3,371			-3,371
Balance at Dec. 31, 2012	866	1,939,628	1,533,768	474	3,474,736
Balance, shares at Dec. 31, 2012	86,596
Increase (Decrease) in Stockholders' Equity
Dividends			-48,423		-48,423
Net income			564,689		564,689
Unrealized change in fair value of investments, net of tax				715	715
Issuance of restricted stock awards	6	-6
Issuance of restricted stock awards, shares	579
Common stock reacquired and retired	-1	-10,100			-10,101
Common stock reacquired and retired, shares	-153
Restricted stock forfeited and retired	-2	2
Restricted stock forfeited and retired, shares	-171
Exercise of stock options	3	14,491			14,494
Exercise of stock options, shares	276
Vesting of restricted stock units, shares	25
Stock-based compensation		26,098			26,098
Balance at Dec. 31, 2013	872	1,970,113	2,050,034	1,189	4,022,208
Balance, shares at Dec. 31, 2013	87,152
Increase (Decrease) in Stockholders' Equity
Dividends			-55,664		-55,664
Net income			507,204		507,204
Unrealized change in fair value of investments, net of tax				-87	-87
Issuance of restricted stock awards	4	-4
Issuance of restricted stock awards, shares	487
Common stock reacquired and retired	-1	-13,559			-13,560
Common stock reacquired and retired, shares	-123
Restricted stock forfeited and retired	-1	1
Restricted stock forfeited and retired, shares	-135
Exercise of stock options	2	11,896			11,898
Exercise of stock options, shares	211
Stock-based compensation		28,633			28,633
Balance at Dec. 31, 2014	$876	$1,997,080	$2,501,574	$1,102	$4,500,632
Balance, shares at Dec. 31, 2014	87,592

BASIS_OF_PRESENTATION_AND_SUMM

BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2014
Basis of Presentation
BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	1. BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
	Cimarex Energy Co., a Delaware corporation, is an independent oil and gas exploration and production company. Our operations are mainly located in Texas, Oklahoma and New Mexico.
	Basis of presentation
	Our Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States of America, or GAAP. Our significant accounting policies are discussed below. The accounts of Cimarex and its subsidiaries are presented in the accompanying Consolidated Financial Statements. All intercompany accounts and transactions were eliminated in consolidation.
	Segment Information
	We have determined that our business is comprised of only one segment because our gathering, processing and marketing activities are ancillary to our production operations and are not separately managed.
	Use of estimates
	The preparation of our financial statements in conformity with GAAP requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues, and expenses. 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.
	The process of estimating quantities of oil and gas reserves is complex, requiring significant decisions in the evaluation of all available geological, geophysical, engineering and economic data. The data for a given field may also change substantially over time as a result of numerous factors including, but not limited to, additional development activity, evolving production history and continual reassessment of the viability of production under varying economic conditions. As a result, material revisions to existing reserve estimates may occur from time to time. Although every reasonable effort is made to ensure that our reserve estimates represent the most accurate assessments possible, subjective decisions and available data for our various fields make these estimates generally less precise than other estimates included in financial statement disclosures.
	Estimates and judgments are also required in determining allowance for doubtful accounts, impairments of undeveloped properties and other assets, purchase price allocation, valuation of deferred tax assets, fair value measurements, and commitments and contingencies. We analyze our estimates, including those related to oil, gas and NGL revenues, and base our estimates on historical experience and various other assumptions that we believe to be reasonable under the circumstances. Actual results may differ from these estimates under different assumptions or conditions.
	Cash and Cash Equivalents
	Cash and cash equivalents consist of cash in banks and investments readily convertible into cash, which have original maturities of three months or less. Cash equivalents are stated at cost, which approximates market value.
	Oil and Gas Well Equipment and Supplies
	Our oil and gas well equipment and supplies are valued at the lower of cost or market using weighted average cost.  The steep decline in oil, gas and NGL prices has resulted in fewer drilling rigs running in the United States as companies cut back on their capital expenditures.  Through the first part of February 2015, published oil rig counts are at their lowest since December 2011.  The effect of lower exploration and development activity, and thus lower demand, will create downward pressure on the price of oil and gas well equipment and supplies.  GAAP requires that these assets are to be carried at the lower of cost or market.  Declines in prices related to our oil and gas well equipment and supplies will likely result in impairments in future quarters.
	Oil and Gas Properties
	We use the full cost method of accounting for our oil and gas operations. All costs associated with property acquisition, exploration, and development activities are capitalized. Exploration and development costs include dry hole costs, geological and geophysical costs, direct overhead related to exploration and development activities, and other costs incurred for the purpose of finding oil and gas reserves. Salaries and benefits paid to employees directly involved in the exploration and development of properties, as well as other internal costs that can be directly identified with acquisition, exploration, and development activities, are also capitalized. Under the full cost method of accounting, no gain or loss is recognized upon the disposition of oil and gas properties unless such disposition would significantly alter the relationship between capitalized costs and proved reserves.
	Companies that follow the full cost accounting method are required to make quarterly ceiling test calculations. This test ensures that total capitalized costs for oil and gas properties (net of accumulated DD&A and deferred income taxes) do not exceed 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. We currently do not have any unproven properties that are being amortized. Revenue calculations in the reserves are based on the unweighted average first-day-of-the-month prices for the prior 12 months. Changes in proved reserve estimates (whether based upon quantity revisions or commodity prices) will cause corresponding changes to the full cost ceiling limitation. If net capitalized costs subject to amortization exceed this limit, the excess would be charged to expense. Any recorded impairment of oil and gas properties is not reversible at a later date.
	Our quarterly and annual ceiling tests are primarily impacted by commodity prices, reserve quantities added and produced, overall exploration and development costs and depletion expense. As of December 31, 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 8% or more in the value of the ceiling limitation would have resulted in an impairment. If commodity prices stay at the current early 2015 levels or decline further, we will incur full cost ceiling impairments in future quarters. Because the ceiling calculation uses rolling 12-month average commodity prices, the effect of lower quarter-over-quarter prices in 2015 compared to 2014 is a lower ceiling value each quarter.  This will result in ongoing impairments each quarter until prices stabilize or improve.  Impairment charges would not affect cash flow from operating activities, but would adversely affect our net income and stockholders’ equity.
	Depletion of proved oil and gas properties is computed on the units- of-production method, whereby capitalized costs, including future development costs and asset retirement obligations, are amortized over total estimated proved reserves. Changes in our estimate of proved reserve quantities, commodity prices and impairment of oil and gas properties will cause corresponding changes in depletion expense in periods subsequent to these changes.
	The capitalized costs of unproved properties, including those in wells in progress, are excluded from the costs being amortized. We do not have major development projects that are excluded from costs being amortized. On a quarterly basis, we evaluate excluded costs for inclusion in the costs to be amortized resulting from the determination of proved reserves or impairments. To the extent that the evaluation indicates these properties are impaired, the amount of the impairment is added to the capitalized costs to be amortized. Expenditures for maintenance and repairs are charged to production expense in the period incurred.
	Fixed assets, net
	Fixed assets consist primarily of gathering and plant facilities, vehicles, airplanes, office furniture, and computer equipment and software.  These items are recorded at cost and are depreciated on the straight-line method based on expected lives of the individual assets, which range from 3 to 30 years.
	Goodwill
	Goodwill represents the excess of the purchase price of business combinations over the fair value of the net assets acquired and is tested for impairment at least annually. We first assess qualitative factors to determine whether it is more likely than not (with a greater than 50% threshold) that the fair value of a reporting unit is less than its carrying amount as a basis for determining whether it is necessary to perform the two-step goodwill impairment test. If goodwill is determined to be impaired then it is written down to a calculated fair value by charging the impairment to expense.
	We evaluate our goodwill for impairment in the fourth quarter of each year or whenever events or changes in circumstances indicate the possibility that goodwill may be impaired. Based upon our qualitative assessment at December 31, 2014, goodwill was not impaired. It is possible that goodwill could become impaired in the future if commodity prices or other economic factors become less favorable.
	Revenue Recognition
	Oil, Gas and NGL Sales
	Revenue is recorded from the sales of oil, gas and NGLs when the product is delivered at a fixed or determinable price, title has transferred and collectability is reasonably assured.  There is a ready market for our products and sales occur soon after production.
	Under certain contracts, when NGLs are extracted from the gas stream, processors receive 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.  Increasing NGL production combined with the impact of recent changes to these contracts has resulted in processing costs becoming more significant.  Accordingly, we have changed our policy to record these processing costs with operating costs as allowed under EITF 00-10.  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 2014 was that total revenue was $51.4 million higher with an offsetting increase in total transportation, processing and other operating 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.
	Marketing Sales
	We market and sell natural gas for working interest owners under short term sales and supply agreements and earn a fee for such services. Revenues are recognized as gas is delivered and are reflected net of gas purchases on the consolidated statements of income and comprehensive income.
	Gas Imbalances
	We use the sales method of accounting for gas imbalances. Under this method, revenue is recorded on the basis of gas actually sold. Gas reserves are adjusted to the extent there are sufficient quantities of natural gas to make up an imbalance. A liability is established in situations where there are insufficient proved reserves available to make-up an overproduced imbalance.  Imbalances have not been significant in the periods presented.
	General and Administrative Expenses
	General and administrative expenses are reported net of amounts reimbursed by working interest owners of the oil and gas properties operated by Cimarex and net of amounts capitalized pursuant to the full cost method of accounting.
	Derivatives
	Our derivative contracts are recorded on the balance sheet at fair value. Our firm sales contracts qualify for the normal purchase and normal sale exception. Contracts that qualify for this treatment do not require mark-to-market accounting treatment. See Note 5 for additional information regarding our derivative instruments.
	Income Taxes
	Cimarex records deferred tax assets and liabilities to account for the expected future tax consequences of events that have been recognized in the financial statements and tax returns.  The company routinely assesses the realizability of its deferred tax assets.  If the company concludes that it is more likely than not that some or all of the deferred tax assets will not be realized, the tax asset is reduced by a valuation allowance.  Numerous judgments and assumptions are inherent in the determination of future taxable income, including factors such as future operating conditions (particularly as related to prevailing oil and gas prices) and changing tax laws.
	The company regularly assesses and, if required, establishes accruals for tax contingencies that could result from assessments of additional tax by taxing jurisdictions where the company operates.  See Note 10 for additional information regarding our income taxes.
	Contingencies
	A provision for contingencies is charged to expense when the loss is probable and the cost can be reasonably estimated. Determining when expenses should be recorded for these contingencies and the appropriate amounts for accrual is a complex estimation process that includes subjective judgment. In many cases, this judgment is based on interpretation of laws and regulations, which can be interpreted differently by regulators and/or courts of law. We closely monitor known and potential legal, environmental, and other contingencies and periodically determine when we should record losses for these items based on information available to us. See Note 11 for additional information regarding our contingencies.
	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 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 current portions of the asset retirement obligations are recorded in “accrued liabilities, other” in the accompanying consolidated balance sheets and expenditures are classified as cash used in operating activities in the accompanying consolidated statements of cash flows.  See Note 9 for additional information regarding our asset retirement obligations.
	Stock-based Compensation
	We recognize compensation related to all stock-based awards, including stock options, in the financial statements based on their estimated grant-date fair value. We grant various types of stock-based awards including stock options, restricted stock (including awards with service-based vesting and market condition-based vesting provisions) and restricted stock units. The fair value of stock option awards is determined using the Black-Scholes option pricing model. Service-based restricted stock and units are valued using the market price of our common stock on the grant date. The fair value of the market condition-based restricted stock is based on the grant-date market value of the award utilizing a statistical analysis. Compensation cost is recognized ratably over the applicable vesting period. To the extent compensation cost relates to employees directly involved in oil and gas acquisition, exploration and development activities, such amounts are capitalized to oil and gas properties. Amounts not capitalized to oil and gas properties are recognized as stock compensation expense. See Note 7 for additional information regarding our stock-based compensation.
	Earnings per Share
	We calculate earnings (loss) per share recognizing that unvested share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents are “participating securities” and therefore should be included in computing earnings per share using the two-class earnings allocation method. The two-class method is an earnings allocation formula that determines earnings per share for each class of common stock and participating security according to dividends declared (or accumulated) and participation rights in undistributed earnings. Our unvested share based payment awards, consisting of restricted stock and units qualify as participating securities.  See Note 8 for additional information regarding our earnings per share.
	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 potential impact of this guidance, but at this time, do not expect that the adoption of this standard will have a material effect on our financial position or results of operation.
	Subsequent Events
	The accompanying financial disclosures include an evaluation of subsequent events through the date of this filing.

LONGTERM_DEBT

LONG-TERM DEBT	12 Months Ended
	Dec. 31, 2014
Long-Term Debt
Long-Term Debt	2. LONG-TERM DEBT
	A summary of our debt is as follows:
		December 31,
	(in thousands)	2014		2013
	Bank debt	$	—	$	174,000
	5.875% Senior Notes,  due May 1, 2022		750,000		750,000
	4.375% Senior Notes,  due June 1, 2024		750,000		—
	Total long-term debt	$	1,500,000	$	924,000
	All of our long-term debt is senior unsecured debt and is, therefore, pari passu with respect to the payment of both principal and interest.
	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 December 31, 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 December 31, 2014, we were in compliance with all of the financial and non-financial covenants.
	Senior Notes
	In June 2014, we issued $750 million of 4.375% senior notes due 2024 and received net proceeds of $740.9 million, after deducting offering discounts and costs.  The net proceeds were used to pay outstanding bank debt and for general corporate purposes.
	In April 2012, we issued $750 million of 5.875% senior notes due 2022 and received net proceeds of $737.0 million, after deducting underwriting discounts and offering costs.  We used a portion of the net proceeds to retire our 7.125% senior notes and the remaining proceeds were used to pay outstanding bank debt and for general corporate purposes.
	In the second quarter of 2012, we completed a cash tender offer to purchase all of our outstanding 7.125% senior notes. We recognized a $16.2 million loss on early extinguishment of debt during the second quarter of 2012.
	Each of our outstanding senior notes is governed by an indenture containing certain covenants, events of default and other restrictive provisions.  Interest on each of the senior notes is payable semi-annually.

PROPERTY_SALES_AND_ACQUISITION

PROPERTY SALES AND ACQUISITIONS	12 Months Ended
	Dec. 31, 2014
Property Acquisitions and Sales
Property Acquisitions and Sales	3. PROPERTY SALES AND ACQUISITIONS
	The following sales and acquisitions were made in the ordinary course of business. All amounts are net of customary purchase price adjustments.
	We sold interests in various non-core oil and gas properties for $446.1 million during 2014. Most of the proceeds were related to sales of producing gas wells in southwestern Kansas and undeveloped acreage in Reagan County, Texas.  During 2014, we made property acquisitions totaling $249.7 million, most of which were in our Cana-Woodford shale play in Western Oklahoma.
	In 2013, we sold interests in non-core oil and gas assets for $61.5 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. Total property acquisitions during 2013 were $37.1 million, mostly for undeveloped acreage in Reeves County, Texas.
	During 2012, we sold interests in non-core oil and gas assets for $306 million. Of this total, $290 million was related to non-core oil and gas assets located in Texas. We had property acquisitions of $33.5 million during 2012, most of which were undeveloped acreage in the Permian Basin.

FAIR_VALUE_MEASUREMENTS

FAIR VALUE MEASUREMENTS	12 Months Ended
	Dec. 31, 2014
Fair Value Measurements
Fair Value Measurements	4. 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 December 31, 2014 and 2013.
	December 31, 2014:	Carrying		Fair
	(in thousands)	Amount		Value
	Financial Assets (Liabilities):
	5.875% Notes due 2022	$	-750,000	$	-776,250
	4.375% Notes due 2024	$	-750,000	$	-720,000
	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 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 year 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 5 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. Included in “accrued liabilities, other” at December 31, 2014 and 2013, respectively, are liabilities of approximately $42.0 million and $43.7 million representing the amount by which checks issued, but not yet presented to our banks for collection, exceeded balances in applicable bank accounts. Also included in “accrued liabilities, other” at December 31, 2014 and 2013, respectively, are accrued payroll related general and administrative expenses of $44.2 million and $41.9 million.
	Our accounts receivable are primarily from either purchasers of our gas, oil and NGL production (customers) or from exploration and production companies which own interests in properties we operate. This industry concentration has the potential to impact our overall exposure to credit risk, either positively or negatively, because our customers and joint working interest owners may be similarly affected by changes in industry conditions.
	We conduct credit analyses prior to making any sales to new customers or increasing credit for existing customers and may require parent company guarantees, letters of credit or prepayments when deemed necessary.
	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 December 31, 2014, the allowance for doubtful accounts totaled $1.5 million. At December 31, 2013, the allowance for doubtful accounts was $6.0 million.
	Major Customers
	Our major customers during 2014 were Enterprise Products Partners L.P. (Enterprise), Sunoco Logistics Partners L.P. (Sunoco) and Oneok Partners, L.P. (Oneok). Enterprise and Sunoco each accounted for 19% of our consolidated revenues in 2014. Oneok accounted for 10% of our 2014 consolidated revenues.  During 2013, Enterprise and Sunoco were our major customers and accounted for 24% and 22% of our consolidated revenues, respectively.
	Enterprise is a significant oil purchaser in Oklahoma and West Texas. Sunoco is a significant purchaser of our oil in Southeast New Mexico and Canadian County, Oklahoma. If either of these entities were to stop purchasing our production, we believe there are a number of other purchasers to whom we could sell our production with some delay. If both parties were to discontinue purchasing our product, there would be challenges initially, but ample markets to handle the disruption.
	Oneok primarily purchases our NGLs and provides gathering, compression and processing services for the majority of our Mid-Continent region gas production.  In the event Oneok ceased buying our NGLs, a minimal impact would occur as these products are piped to various processing and storage market areas where we could sell to a different purchaser. In the event Oneok ceased gathering, compressing, and processing our gas, there would be challenges initially, but several other entities exist to fill in the gap.

DERIVATIVE_INSTRUMENTSHEDGING

DERIVATIVE INSTRUMENTS/HEDGING	12 Months Ended
	Dec. 31, 2014
Derivative Instruments/Hedging
Derivative Instruments/Hedging	5. 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.
	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 presents the net gains and (losses) from settlements and changes in fair value of our derivative contracts, and the gains (losses) only from settlements during the periods shown below.
	(in thousands)	2014			2013			2012
	Gain (loss) on derivative instruments, net	$	3,762		$	-209		$	245
	Settlement gains (losses)	$	7,641		$	-4,088		$	—
	Our derivative contracts are carried at their fair value on our balance sheet using Level 2 inputs and 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.  We entered into oil and gas contracts at the end of 2013 and the beginning of 2014. All of these contracts were settled as of December 31, 2014 and we have not entered into any new contracts.  Depending on oil and gas futures markets and management’s view of underlying supply and demand trends, we may hedge in the future.
	The following table presents the amounts and classifications of our derivative assets and liabilities as of December 31, 2013, as well as the potential effect of netting arrangements on contracts with the same counterparty.
	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 were exposed to financial risks associated with our derivative contracts from non-performance by our counterparties. We mitigated our exposure to any single counterparty by contracting with a number of financial institutions, each of which had a high credit rating and was 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.

CAPITAL_STOCK

CAPITAL STOCK	12 Months Ended
	Dec. 31, 2014
Capital Stock
Capital Stock	6. CAPITAL STOCK
	Authorized capital stock consists of 200 million shares of common stock and 15 million shares of preferred stock. At December 31, 2014, there were no shares of preferred stock outstanding.  See our Consolidated Statements of Stockholders’ Equity for detailed capital stock activity.
	Dividends
	A cash dividend has been paid to stockholders in every quarter since the first quarter of 2006. In February 2014, the quarterly dividend was increased to $0.16 per share from $0.14 per share. Future dividend payments will depend on our level of earnings, financial requirements and other factors considered relevant by the Board of Directors.
		2014		2013		2012
	Dividend declared (in millions)	$	55.7	$	48.4	$	41.3
	Dividend per share	$	0.64	$	0.56	$	0.48

STOCKBASED_and_OTHER_COMPENSAT

STOCK-BASED and OTHER COMPENSATION	12 Months Ended
	Dec. 31, 2014
STOCK-BASED AND OTHER COMPENSATION
Stock-based compensation and other compensation	7. STOCK-BASED and OTHER COMPENSATION
	We have recognized non-cash stock-based compensation cost as follows:
			Years Ended December 31,
	(in thousands)		2014			2013			2012
	Performance stock awards		$	12,141		$	11,105		$	19,066
	Service-based stock awards			13,607			12,018			12,231
	Restricted stock awards			25,748			23,123			31,297
	Stock option awards			3,057			3,145			2,889
				28,805			26,268			34,186
	Less amounts capitalized to oil and gas properties			-13,804			-11,989			-12,267
	Compensation expense		$	15,001		$	14,279		$	21,919
	Historical amounts may not be representative of future amounts as additional awards may be granted. The 2012 compensation cost for the performance awards includes $3.9 million of accelerated vesting related to the death of former Chairman, F.H. Merelli.  In addition, the 2013 cost for performance awards is approximately $4.3 million lower than 2012 costs due to the timing of awards granted.  Almost all of the performance awards granted in 2013 were awarded in mid-December.  Awards granted in early January of 2010 were fully amortized in January of 2013, resulting in 2013 having less costs amortized during the year.
	Equity Incentive Plan
	Our 2014 Equity Incentive Plan (the 2014 Plan) was approved by stockholders in May 2014 and our previous plan was terminated at that time. Outstanding awards under the previous plan were not impacted. A total of 6.6 million shares of common stock may be issued under the 2014 Plan, including shares available from the previous plan. 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.
	Restricted Stock
	The following table provides information about restricted stock awards granted during the last three years.
			Years Ended December 31,
			2014					2013					2012
					Weighted					Weighted				Weighted
					Average					Average				Average
			Number		Grant-Date			Number		Grant-Date			Number	Grant-Date
			of Shares		Fair Value			of Shares		Fair Value			of Shares	Fair Value
	Performance stock awards		316,441		$	83.22		298,000		$	77.75		262,770	$	43.22
	Service-based stock awards		170,402		$	136.72		281,236		$	72.89		299,499	$	54.17
	Total restricted stock awards		486,843		$	101.95		579,236		$	75.39		562,269	$	49.05
	Performance awards were 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 provides information on restricted stock activity during the year.
								Performance
			Service-based					(subject to market conditions)
					Weighted					Weighted
					Average					Average
					Grant-Date					Grant-Date
			Awards		Fair Value			Awards		Fair Value
	Outstanding beginning of period		1,035,032		$	68.41		828,802		$	65.27
	Vested		-106,817		$	37.91		-195,664		$	73.01
	Granted		170,402		$	136.72		316,441		$	83.22
	Canceled		-62,200		$	69.91		-72,368		$	73.01
	Outstanding end of period		1,036,417		$	82.69		877,211		$	69.38
	The total fair value of restricted stock that vested was $34.1 million in 2014, $25.7 million in 2013, and $36.0 million in 2012.
	Unrecognized compensation cost related to unvested restricted shares at December 31, 2014 was $83.9 million. We expect to recognize that cost over a weighted average period of 2.2 years.
	Restricted Units
	As of December 31, 2014 and 2013, we had 8,838 restricted units outstanding. These 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.
	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 (NYSE) 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 NYSE on the date of grant.
	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.
	The following summarizes the options granted and related information, and the assumptions used to determine the fair value of those options.
			Years Ended December 31,
			2014			2013			2012
	Options granted			82,500			144,400			152,800
	Weighted average grant-date fair value		$	41.69		$	21.64		$	20.55
	Weighted average exercise price		$	139.02		$	72.25		$	51.92
	Total Fair Value (in thousands)		$	3,439		$	3,125		$	3,140
	Expected years until exercise			4.0			4.0			5.3
	Expected stock volatility			36.7	%		38.6	%		47.4	%
	Dividend yield			0.5	%		0.8	%		0.9	%
	Risk-free interest rate			1.8	%		1.4	%		0.6	%
	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		-211,258		$	56.32
Granted		82,500		$	139.02
Forfeited		-18,176		$	70.67
Outstanding as of December 31, 2014		384,082		$	78.19		5.0	Years		$	13,260
Exercisable as of December 31, 2014		178,926		$	59.19		4.1	Years		$	8,319
The following table provides information regarding options exercised and the grant-date fair value of options vested.
		Years Ended December 31,
(in thousands)		2014			2013			2012
Number of options exercised			211,258			276,069			558,419
Cash received from option exercises		$	11,899		$	14,494		$	11,433
Tax benefit from option exercises included in paid-in-capital (1)		$	—		$	—		$	76
Intrinsic value of options exercised		$	15,384		$	10,109		$	22,482
Grant-date fair value of options vested		$	4,419		$	2,521		$	2,560
	-1		No tax benefit is recorded until the benefit reduces current taxes payable.
The following summary reflects the status of non-vested stock options as of December 31, 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
Vested		-202,182		$	21.86		$	62.48
Granted		82,500		$	41.69		$	139.02
Forfeited		-18,176		$	23.24		$	70.67
Non-vested as of December 31, 2014		205,156		$	29.35		$	94.76
As of December 31, 2014, there was $4.1 million of unrecognized compensation cost related to non-vested stock options. We expect to recognize that cost on a pro rata basis over a weighted average period of 1.8 years.
Other Compensation
We maintain and sponsor a contributory 401(k) plan for our employees. Annual costs related to the plan were $11.0 million for 2014. During 2013 and 2012, such costs were $9.0 million and $8.2 million, respectively.

EARNINGS_PER_SHARE

EARNINGS PER SHARE	12 Months Ended
	Dec. 31, 2014
Earnings per Share
Earnings per Share	8. EARNINGS PER SHARE
	The calculations of basic and diluted net earnings per common share under the two-class method are presented below.
			Years Ended December 31,
	(in thousands, except per share data)		2014		2013		2012
	Basic:
	Net income		$	507,204	$	564,689	$	353,823
	Participating securities’ share in earnings			-9,906		-11,091		-6,753
	Net income applicable to common stockholders		$	497,298	$	553,598	$	347,070
	Diluted:
	Net income		$	507,204	$	564,689	$	353,823
	Participating securities’ share in earnings			-9,891		-11,076		-6,732
	Net income applicable to common stockholders		$	497,313	$	553,613	$	347,091
	Shares:
	Basic shares outstanding			85,679		85,288		84,757
	Incremental shares from assumed exercise of stock options			131		121		277
	Fully diluted common stock			85,810		85,409		85,034
	Excluded (1)			94		251		414
	Earnings per share to common stockholders (2):
	Basic		$	5.79	$	6.48	$	4.08
	Diluted		$	5.78	$	6.47	$	4.07
		-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.

ASSET_RETIREMENT_OBLIGATIONS

ASSET RETIREMENT OBLIGATIONS	12 Months Ended
	Dec. 31, 2014
Asset Retirement Obligations
Asset Retirement Obligations	9. ASSET RETIREMENT OBLIGATIONS
	The following table reflects the components of the change in the carrying amount of the asset retirement obligation for the years ended December 31, 2014 and 2013.
	(in thousands)	2014		2013
	Asset retirement obligation at January 1,	$	154,026	$	185,138
	Liabilities incurred		13,015		5,547
	Liability settlements and disposals		-27,036		-47,842
	Accretion expense		7,583		7,871
	Revisions of estimated liabilities		25,420		3,312
	Asset retirement obligation at December 31,		173,008		154,026
	Less current obligation		13,216		27,058
	Long-term asset retirement obligation	$	159,792	$	126,968
	During 2014, the liability settlements and disposals included $11.2 million related to properties that were sold.  Also during this period we recognized revisions of estimated liabilities totaling $25.4 million, which were due to changes in abandonment cost and timing estimates.  During 2013, the liability settlements and disposals included $4.4 million related to properties that were sold.

INCOME_TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2014
Income Taxes
Income Taxes	10. INCOME TAXES
	Federal income tax expense (benefit) for the years presented differs from the amounts that would be provided by applying the U.S. Federal income tax rate, primarily due to the effect of state income taxes. The components of the provision for income taxes are as follows:
		Years Ended December 31,
	(in thousands)	2014		2013		2012
	Current Taxes:
	Federal (benefit)	$	—	$	-381	$	-1,629
	State (benefit)		404		-308		140
			404		-689		-1,489
	Deferred taxes:
	Federal		282,729		315,165		199,459
	State		15,564		14,535		8,757
			298,293		329,700		208,216
		$	298,697	$	329,011	$	206,727
	Reconciliations of the income tax expense calculated at the federal statutory rate of 35% to the total income tax  expense are as follows:
		Years Ended December 31,
	(in thousands)	2014		2013		2012
	Provision at statutory rate	$	282,066	$	312,795	$	196,192
	Effect of state taxes		15,826		14,226		8,902
	Domestic Production Activities allowance		—		—		567
	Other permanent differences		805		1,990		1,066
	Income tax expense	$	298,697	$	329,011	$	206,727
	The components of Cimarex’s net deferred tax liabilities are as follows:
		December 31,
	(in thousands)	2014		2013
	Long-term:
	Assets:
	Stock compensation and other accrued amounts	$	26,527	$	24,815
	Net operating loss carryforward, net of valuation allowance		218,584		207,282
	Credit carryforward		4,068		4,068
			249,179		236,165
	Liabilities:
	Property, plant and equipment		-2,003,885		-1,696,006
	Net, long-term deferred tax liability		-1,754,706		-1,459,841
	Current:
	Assets:
	Other accrued amounts		13,475		16,854
			13,475		16,854
	Net deferred tax liabilities	$	-1,741,231	$	-1,442,987
	At December 31, 2014, the company had a U.S. net tax operating loss carryforward of approximately $651.1 million, which would expire in years 2031 through 2034. We believe that the carryforward will be utilized before it expires. The company recorded an increase to its net operating loss carryforward at December 31, 2014 for certain state losses.  A corresponding valuation allowance of $19.1 million was established since it is not more likely than not that these additional state net operating losses will be utilized before they expire.  The amount of the U.S. net tax operating loss carryforward that will be recorded to equity when utilized to reduce taxes payable is $83.1 million. We also had an alternative minimum tax credit carryforward of approximately $4.1 million.
	At December 31, 2014 and 2013, we had no unrecognized tax benefits that would impact our effective rate and we have made no provisions for interest or penalties related to uncertain tax positions. The tax years 2011 through 2013 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 2010 through 2013 tax years.

COMMITMENTS_AND_CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies
Commitments and Contingencies	11. COMMITMENTS AND CONTINGENCIES
	Lease Commitments
	We have various commitments for office space and equipment under operating lease arrangements. Rent expense for the operating leases totaled $14.3 million in 2014. Rent expense was $13.2 million and $5.7 million for 2013 and 2012, respectively. The increases in rent expense over the periods were due to additional costs associated with office relocations and entering into new lease arrangements.
	Shown below are future minimum cash payments required under these leases as of December 31, 2014.
	(in thousands)	Operating
		Leases
	2015	$	10,166
	2016		11,261
	2017		10,789
	2018		10,416
	2019		10,522
	Later years		67,795
	Total future minimum lease payments	$	120,949
	Other Commitments
	We have commitments of $207.7 million to finish drilling and completing wells in progress at December 31, 2014. We also have various commitments for drilling rigs. The total minimum expenditure commitments under these agreements are $51.7 million.
	In New Mexico and Texas, we are constructing gathering facilities and pipelines. At December 31, 2014, we had commitments of $6.9 million relating to these construction projects.
	At December 31, 2014, we had firm sales contracts to deliver approximately 30.8 Bcf of natural gas over the next 12 months. If this gas is not delivered, our financial commitment would be approximately $91.7 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.
	We have other various transportation and delivery commitments in the normal course of business, which are not material individually or in the aggregate.
	All of the noted commitments were routine and were made in the normal course of our business.
	Litigation
	In the normal 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, the resolution of them we believe, 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 2008, we recorded litigation expense of $119.6 million for the H.B. Krug, et al. v. Helmerich & Payne, Inc. (H&P) lawsuit, and began accruing additional post-judgment interest and costs for this case.
	Over the years, the lawsuit has been disputed until December 13, 2013 when the Oklahoma Supreme Court reversed the Tulsa County District Court’s original judgment of $119.6 million and affirmed an alternative jury verdict for $3.65 million.  It also remanded the case back to the trial court for consideration of potential prejudgment interest, attorney’s fees and cost awards.  Accordingly, on December 31, 2013 we reduced the previously recognized litigation expense, which included related interest and costs, and the associated long-term liability by $142.8 million.
	On April 1, 2014, Cimarex paid the Plaintiffs $15.8 million in satisfaction of the $3.65 million damages award, the post-judgment interest award and the payment in lieu of bond, all of which are now final and not appealable.  On June 24, 2014, the trial court ruled the Plaintiffs were not entitled to prejudgment interest but were entitled to attorney’s fees and costs, the amount of which will be determined at a subsequent hearing.  On July 31, 2014, the Plaintiffs appealed the trial court’s denial of prejudgment interest, which will be determined by the Oklahoma Supreme Court.  The outcome of these remaining issues cannot be determined, and our current estimates and assessments likely will change, as a result of these future legal proceedings.
	Hitch Enterprises, Inc. et al. v. Cimarex Energy Co.
	On December 11, 2012, Cimarex entered into a preliminary resolution of the Hitch Enterprises, Inc., et al. v. Cimarex Energy Co., et al.  (Hitch) litigation matter for $16.4 million. Hitch is a statewide royalty class action pending in the Federal District Court in Oklahoma City, Oklahoma. The settlement was reached at a mediation, which occurred after the parties began to exchange information, including damage analyses, on November 16, 2012. On July 2, 2013, the Court entered a judgment approving the parties’ settlement. The judgment became final and unappealable on August 2, 2013. Cimarex distributed the settlement proceeds pursuant to the Court’s order in September 2013 and the administration of the settlement is ongoing. In the fourth quarter of 2012, we accrued $16.4 million for this matter.

RELATED_PARTY_TRANSACTIONS

RELATED PARTY TRANSACTIONS	12 Months Ended
	Dec. 31, 2014
RELATED PARTY TRANSACTIONS
RELATED PARTY TRANSACTIONS	12. RELATED PARTY TRANSACTIONS
	Helmerich & Payne, Inc. (H&P) provides contract drilling services to Cimarex. Drilling costs of approximately $18.4 million were incurred by Cimarex related to such services for 2014. During 2013 and 2012, such costs were $17.0 million and $20.8 million, respectively. Hans Helmerich, a director of Cimarex, is Chairman of the Board of Directors of H&P.
	Jerry Box, a director of Cimarex, was the non-executive Chairman of the Board of Newpark through May 2014.  Certain subsidiaries of Newpark Resources, Inc. have provided various drilling services to Cimarex. Costs of such services were $0.6 million through May 2014. During 2013 and 2012, such costs were $3.5 million and $4.1 million, respectively.

SUPPLEMENTAL_DISCLOSURE_OF_CAS

SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION	12 Months Ended
	Dec. 31, 2014
Supplemental Disclosure of Cash Flow Information:
Supplemental Disclosure of Cash Flow Information:	13. SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
		Years Ended December 31,
	(in thousands)	2014		2013		2012
	Cash paid during the period for:
	Interest expense (including capitalized amounts)	$	66,167	$	50,754	$	42,420
	Interest capitalized	$	32,623	$	29,098	$	30,255
	Income taxes	$	354	$	205	$	377
	Cash received for income taxes	$	460	$	966	$	49,754

BASIS_OF_PRESENTATION_AND_SUMM1

BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2014
Basis of Presentation
Basis of presentation	Basis of presentation
	Our Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States of America, or GAAP. Our significant accounting policies are discussed below. The accounts of Cimarex and its subsidiaries are presented in the accompanying Consolidated Financial Statements. All intercompany accounts and transactions were eliminated in consolidation.
Segment Information	Segment Information
	We have determined that our business is comprised of only one segment because our gathering, processing and marketing activities are ancillary to our production operations and are not separately managed.
Use of Estimates	Use of estimates
	The preparation of our financial statements in conformity with GAAP requires us to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues, and expenses. 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.
	The process of estimating quantities of oil and gas reserves is complex, requiring significant decisions in the evaluation of all available geological, geophysical, engineering and economic data. The data for a given field may also change substantially over time as a result of numerous factors including, but not limited to, additional development activity, evolving production history and continual reassessment of the viability of production under varying economic conditions. As a result, material revisions to existing reserve estimates may occur from time to time. Although every reasonable effort is made to ensure that our reserve estimates represent the most accurate assessments possible, subjective decisions and available data for our various fields make these estimates generally less precise than other estimates included in financial statement disclosures.
	Estimates and judgments are also required in determining allowance for doubtful accounts, impairments of undeveloped properties and other assets, purchase price allocation, valuation of deferred tax assets, fair value measurements, and commitments and contingencies. We analyze our estimates, including those related to oil, gas and NGL revenues, and base our estimates on historical experience and various other assumptions that we believe to be reasonable under the circumstances. Actual results may differ from these estimates under different assumptions or conditions.
Cash and Cash Equivalents	Cash and Cash Equivalents
	Cash and cash equivalents consist of cash in banks and investments readily convertible into cash, which have original maturities of three months or less. Cash equivalents are stated at cost, which approximates market value.
Oil and Gas Properties	Oil and Gas Well Equipment and Supplies
	Our oil and gas well equipment and supplies are valued at the lower of cost or market using weighted average cost.  The steep decline in oil, gas and NGL prices has resulted in fewer drilling rigs running in the United States as companies cut back on their capital expenditures.  Through the first part of February 2015, published oil rig counts are at their lowest since December 2011.  The effect of lower exploration and development activity, and thus lower demand, will create downward pressure on the price of oil and gas well equipment and supplies.  GAAP requires that these assets are to be carried at the lower of cost or market.  Declines in prices related to our oil and gas well equipment and supplies will likely result in impairments in future quarters.
	Oil and Gas Properties
	We use the full cost method of accounting for our oil and gas operations. All costs associated with property acquisition, exploration, and development activities are capitalized. Exploration and development costs include dry hole costs, geological and geophysical costs, direct overhead related to exploration and development activities, and other costs incurred for the purpose of finding oil and gas reserves. Salaries and benefits paid to employees directly involved in the exploration and development of properties, as well as other internal costs that can be directly identified with acquisition, exploration, and development activities, are also capitalized. Under the full cost method of accounting, no gain or loss is recognized upon the disposition of oil and gas properties unless such disposition would significantly alter the relationship between capitalized costs and proved reserves.
	Companies that follow the full cost accounting method are required to make quarterly ceiling test calculations. This test ensures that total capitalized costs for oil and gas properties (net of accumulated DD&A and deferred income taxes) do not exceed 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. We currently do not have any unproven properties that are being amortized. Revenue calculations in the reserves are based on the unweighted average first-day-of-the-month prices for the prior 12 months. Changes in proved reserve estimates (whether based upon quantity revisions or commodity prices) will cause corresponding changes to the full cost ceiling limitation. If net capitalized costs subject to amortization exceed this limit, the excess would be charged to expense. Any recorded impairment of oil and gas properties is not reversible at a later date.
	Our quarterly and annual ceiling tests are primarily impacted by commodity prices, reserve quantities added and produced, overall exploration and development costs and depletion expense. As of December 31, 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 8% or more in the value of the ceiling limitation would have resulted in an impairment. If commodity prices stay at the current early 2015 levels or decline further, we will incur full cost ceiling impairments in future quarters. Because the ceiling calculation uses rolling 12-month average commodity prices, the effect of lower quarter-over-quarter prices in 2015 compared to 2014 is a lower ceiling value each quarter.  This will result in ongoing impairments each quarter until prices stabilize or improve.  Impairment charges would not affect cash flow from operating activities, but would adversely affect our net income and stockholders’ equity.
	Depletion of proved oil and gas properties is computed on the units- of-production method, whereby capitalized costs, including future development costs and asset retirement obligations, are amortized over total estimated proved reserves. Changes in our estimate of proved reserve quantities, commodity prices and impairment of oil and gas properties will cause corresponding changes in depletion expense in periods subsequent to these changes.
	The capitalized costs of unproved properties, including those in wells in progress, are excluded from the costs being amortized. We do not have major development projects that are excluded from costs being amortized. On a quarterly basis, we evaluate excluded costs for inclusion in the costs to be amortized resulting from the determination of proved reserves or impairments. To the extent that the evaluation indicates these properties are impaired, the amount of the impairment is added to the capitalized costs to be amortized. Expenditures for maintenance and repairs are charged to production expense in the period incurred.
Fixed assets, net	Fixed assets, net
	Fixed assets consist primarily of gathering and plant facilities, vehicles, airplanes, office furniture, and computer equipment and software.  These items are recorded at cost and are depreciated on the straight-line method based on expected lives of the individual assets, which range from 3 to 30 years.
Goodwill	Goodwill
	Goodwill represents the excess of the purchase price of business combinations over the fair value of the net assets acquired and is tested for impairment at least annually. We first assess qualitative factors to determine whether it is more likely than not (with a greater than 50% threshold) that the fair value of a reporting unit is less than its carrying amount as a basis for determining whether it is necessary to perform the two-step goodwill impairment test. If goodwill is determined to be impaired then it is written down to a calculated fair value by charging the impairment to expense.
	We evaluate our goodwill for impairment in the fourth quarter of each year or whenever events or changes in circumstances indicate the possibility that goodwill may be impaired. Based upon our qualitative assessment at December 31, 2014, goodwill was not impaired. It is possible that goodwill could become impaired in the future if commodity prices or other economic factors become less favorable.
Revenue Recognition	Revenue Recognition
	Oil, Gas and NGL Sales
	Revenue is recorded from the sales of oil, gas and NGLs when the product is delivered at a fixed or determinable price, title has transferred and collectability is reasonably assured.  There is a ready market for our products and sales occur soon after production.
	Under certain contracts, when NGLs are extracted from the gas stream, processors receive 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.  Increasing NGL production combined with the impact of recent changes to these contracts has resulted in processing costs becoming more significant.  Accordingly, we have changed our policy to record these processing costs with operating costs as allowed under EITF 00-10.  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 2014 was that total revenue was $51.4 million higher with an offsetting increase in total transportation, processing and other operating 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.
	Marketing Sales
	We market and sell natural gas for working interest owners under short term sales and supply agreements and earn a fee for such services. Revenues are recognized as gas is delivered and are reflected net of gas purchases on the consolidated statements of income and comprehensive income.
	Gas Imbalances
	We use the sales method of accounting for gas imbalances. Under this method, revenue is recorded on the basis of gas actually sold. Gas reserves are adjusted to the extent there are sufficient quantities of natural gas to make up an imbalance. A liability is established in situations where there are insufficient proved reserves available to make-up an overproduced imbalance.  Imbalances have not been significant in the periods presented.
General and Administrative Expenses	General and Administrative Expenses
	General and administrative expenses are reported net of amounts reimbursed by working interest owners of the oil and gas properties operated by Cimarex and net of amounts capitalized pursuant to the full cost method of accounting.
Derivatives	Derivatives
	Our derivative contracts are recorded on the balance sheet at fair value. Our firm sales contracts qualify for the normal purchase and normal sale exception. Contracts that qualify for this treatment do not require mark-to-market accounting treatment. See Note 5 for additional information regarding our derivative instruments.
Income Taxes	Income Taxes
	Cimarex records deferred tax assets and liabilities to account for the expected future tax consequences of events that have been recognized in the financial statements and tax returns.  The company routinely assesses the realizability of its deferred tax assets.  If the company concludes that it is more likely than not that some or all of the deferred tax assets will not be realized, the tax asset is reduced by a valuation allowance.  Numerous judgments and assumptions are inherent in the determination of future taxable income, including factors such as future operating conditions (particularly as related to prevailing oil and gas prices) and changing tax laws.
	The company regularly assesses and, if required, establishes accruals for tax contingencies that could result from assessments of additional tax by taxing jurisdictions where the company operates.  See Note 10 for additional information regarding our income taxes.
Contingencies	Contingencies
	A provision for contingencies is charged to expense when the loss is probable and the cost can be reasonably estimated. Determining when expenses should be recorded for these contingencies and the appropriate amounts for accrual is a complex estimation process that includes subjective judgment. In many cases, this judgment is based on interpretation of laws and regulations, which can be interpreted differently by regulators and/or courts of law. We closely monitor known and potential legal, environmental, and other contingencies and periodically determine when we should record losses for these items based on information available to us. See Note 11 for additional information regarding our contingencies.
Asset Retirement Obligations	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 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 current portions of the asset retirement obligations are recorded in “accrued liabilities, other” in the accompanying consolidated balance sheets and expenditures are classified as cash used in operating activities in the accompanying consolidated statements of cash flows.  See Note 9 for additional information regarding our asset retirement obligations.
Stock-based Compensation	Stock-based Compensation
	We recognize compensation related to all stock-based awards, including stock options, in the financial statements based on their estimated grant-date fair value. We grant various types of stock-based awards including stock options, restricted stock (including awards with service-based vesting and market condition-based vesting provisions) and restricted stock units. The fair value of stock option awards is determined using the Black-Scholes option pricing model. Service-based restricted stock and units are valued using the market price of our common stock on the grant date. The fair value of the market condition-based restricted stock is based on the grant-date market value of the award utilizing a statistical analysis. Compensation cost is recognized ratably over the applicable vesting period. To the extent compensation cost relates to employees directly involved in oil and gas acquisition, exploration and development activities, such amounts are capitalized to oil and gas properties. Amounts not capitalized to oil and gas properties are recognized as stock compensation expense. See Note 7 for additional information regarding our stock-based compensation.
Earnings per Share	Earnings per Share
	We calculate earnings (loss) per share recognizing that unvested share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents are “participating securities” and therefore should be included in computing earnings per share using the two-class earnings allocation method. The two-class method is an earnings allocation formula that determines earnings per share for each class of common stock and participating security according to dividends declared (or accumulated) and participation rights in undistributed earnings. Our unvested share based payment awards, consisting of restricted stock and units qualify as participating securities.  See Note 8 for additional information regarding our earnings per share.
Recently Issued Accounting Standards	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 potential impact of this guidance, but at this time, do not expect that the adoption of this standard will have a material effect on our financial position or results of operation.
Subsequent Events	Subsequent Events
	The accompanying financial disclosures include an evaluation of subsequent events through the date of this filing.

LONGTERM_DEBT_Tables

LONG-TERM DEBT (Tables)	12 Months Ended
	Dec. 31, 2014
Long-Term Debt
Summary of debt
		December 31,
	(in thousands)	2014		2013
	Bank debt	$	—	$	174,000
	5.875% Senior Notes,  due May 1, 2022		750,000		750,000
	4.375% Senior Notes,  due June 1, 2024		750,000		—
	Total long-term debt	$	1,500,000	$	924,000

FAIR_VALUE_MEASUREMENTS_Tables

FAIR VALUE MEASUREMENTS (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Measurements
Fair value measurement information for certain assets and liabilities
	December 31, 2014:	Carrying		Fair
	(in thousands)	Amount		Value
	Financial Assets (Liabilities):
	5.875% Notes due 2022	$	-750,000	$	-776,250
	4.375% Notes due 2024	$	-750,000	$	-720,000
	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

DERIVATIVE_INSTRUMENTSHEDGING_

DERIVATIVE INSTRUMENTS/HEDGING (Tables)	12 Months Ended
	Dec. 31, 2014
Derivative Instruments/Hedging
Net gains and (losses) from settlements and changes in fair value of derivative contracts
	(in thousands)	2014			2013			2012
	Gain (loss) on derivative instruments, net	$	3,762		$	-209		$	245
	Settlement gains (losses)	$	7,641		$	-4,088		$	—
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	.
	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		$	—

CAPITAL_STOCK_Tables

CAPITAL STOCK (Tables)	12 Months Ended
	Dec. 31, 2014
Capital Stock
Schedule of dividends declared
		2014		2013		2012
	Dividend declared (in millions)	$	55.7	$	48.4	$	41.3
	Dividend per share	$	0.64	$	0.56	$	0.48

STOCKBASED_and_OTHER_COMPENSAT1

STOCK-BASED and OTHER COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2014
Options, Restricted Stock and Unit Awards
Recognition of non-cash stock-based compensation cost
			Years Ended December 31,
	(in thousands)		2014			2013			2012
	Performance stock awards		$	12,141		$	11,105		$	19,066
	Service-based stock awards			13,607			12,018			12,231
	Restricted stock awards			25,748			23,123			31,297
	Stock option awards			3,057			3,145			2,889
				28,805			26,268			34,186
	Less amounts capitalized to oil and gas properties			-13,804			-11,989			-12,267
	Compensation expense		$	15,001		$	14,279		$	21,919
Restricted Stock [Member]
Options, Restricted Stock and Unit Awards
Restricted stock activity
								Performance
			Service-based					(subject to market conditions)
					Weighted					Weighted
					Average					Average
					Grant-Date					Grant-Date
			Awards		Fair Value			Awards		Fair Value
	Outstanding beginning of period		1,035,032		$	68.41		828,802		$	65.27
	Vested		-106,817		$	37.91		-195,664		$	73.01
	Granted		170,402		$	136.72		316,441		$	83.22
	Canceled		-62,200		$	69.91		-72,368		$	73.01
	Outstanding end of period		1,036,417		$	82.69		877,211		$	69.38
Restricted Stock and Units [Member]
Options, Restricted Stock and Unit Awards
Summary of restricted stock awards granted
			Years Ended December 31,
			2014					2013					2012
					Weighted					Weighted				Weighted
					Average					Average				Average
			Number		Grant-Date			Number		Grant-Date			Number	Grant-Date
			of Shares		Fair Value			of Shares		Fair Value			of Shares	Fair Value
	Performance stock awards		316,441		$	83.22		298,000		$	77.75		262,770	$	43.22
	Service-based stock awards		170,402		$	136.72		281,236		$	72.89		299,499	$	54.17
	Total restricted stock awards		486,843		$	101.95		579,236		$	75.39		562,269	$	49.05
Employee Stock Option [Member]
Options, Restricted Stock and Unit Awards
Summary of information regarding options exercised and grant-date fair value of options vested
			Years Ended December 31,
	(in thousands)		2014			2013			2012
	Number of options exercised			211,258			276,069			558,419
	Cash received from option exercises		$	11,899		$	14,494		$	11,433
	Tax benefit from option exercises included in paid-in-capital (1)		$	—		$	—		$	76
	Intrinsic value of options exercised		$	15,384		$	10,109		$	22,482
	Grant-date fair value of options vested		$	4,419		$	2,521		$	2,560
		-1		No tax benefit is recorded until the benefit reduces current taxes payable.
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
	Vested		-202,182		$	21.86		$	62.48
	Granted		82,500		$	41.69		$	139.02
	Forfeited		-18,176		$	23.24		$	70.67
	Non-vested as of December 31, 2014		205,156		$	29.35		$	94.76
Summary of options granted, weighted average grant-date fair value, total fair value of the options and assumptions used to determine fair market value of those options
			Years Ended December 31,
			2014			2013			2012
	Options granted			82,500			144,400			152,800
	Weighted average grant-date fair value		$	41.69		$	21.64		$	20.55
	Weighted average exercise price		$	139.02		$	72.25		$	51.92
	Total Fair Value (in thousands)		$	3,439		$	3,125		$	3,140
	Expected years until exercise			4.0			4.0			5.3
	Expected stock volatility			36.7	%		38.6	%		47.4	%
	Dividend yield			0.5	%		0.8	%		0.9	%
	Risk-free interest rate			1.8	%		1.4	%		0.6	%
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		-211,258		$	56.32
	Granted		82,500		$	139.02
	Forfeited		-18,176		$	70.67
	Outstanding as of December 31, 2014		384,082		$	78.19		5.0	Years		$	13,260
	Exercisable as of December 31, 2014		178,926		$	59.19		4.1	Years		$	8,319

EARNINGS_PER_SHARE_Tables

EARNINGS PER SHARE (Tables)	12 Months Ended
	Dec. 31, 2013
Earnings per Share
Calculations of basic and diluted net earnings (loss) per common share under the two-class method
			Years Ended December 31,
	(in thousands, except per share data)		2014		2013		2012
	Basic:
	Net income		$	507,204	$	564,689	$	353,823
	Participating securities’ share in earnings			-9,906		-11,091		-6,753
	Net income applicable to common stockholders		$	497,298	$	553,598	$	347,070
	Diluted:
	Net income		$	507,204	$	564,689	$	353,823
	Participating securities’ share in earnings			-9,891		-11,076		-6,732
	Net income applicable to common stockholders		$	497,313	$	553,613	$	347,091
	Shares:
	Basic shares outstanding			85,679		85,288		84,757
	Incremental shares from assumed exercise of stock options			131		121		277
	Fully diluted common stock			85,810		85,409		85,034
	Excluded (1)			94		251		414
	Earnings per share to common stockholders (2):
	Basic		$	5.79	$	6.48	$	4.08
	Diluted		$	5.78	$	6.47	$	4.07
		-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.

ASSET_RETIREMENT_OBLIGATIONS_T

ASSET RETIREMENT OBLIGATIONS (Tables)	12 Months Ended
	Dec. 31, 2014
Asset Retirement Obligations
Change in the carrying amount of the asset retirement obligation
	(in thousands)	2014		2013
	Asset retirement obligation at January 1,	$	154,026	$	185,138
	Liabilities incurred		13,015		5,547
	Liability settlements and disposals		-27,036		-47,842
	Accretion expense		7,583		7,871
	Revisions of estimated liabilities		25,420		3,312
	Asset retirement obligation at December 31,		173,008		154,026
	Less current obligation		13,216		27,058
	Long-term asset retirement obligation	$	159,792	$	126,968

INCOME_TAXES_Tables

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2014
Income Taxes
Components of the provision for income taxes
		Years Ended December 31,
	(in thousands)	2014		2013		2012
	Current Taxes:
	Federal (benefit)	$	—	$	-381	$	-1,629
	State (benefit)		404		-308		140
			404		-689		-1,489
	Deferred taxes:
	Federal		282,729		315,165		199,459
	State		15,564		14,535		8,757
			298,293		329,700		208,216
		$	298,697	$	329,011	$	206,727
Reconciliations of income tax (benefit) expense calculated at federal statutory rate of 35% to the total income tax (benefit) expense
		Years Ended December 31,
	(in thousands)	2014		2013		2012
	Provision at statutory rate	$	282,066	$	312,795	$	196,192
	Effect of state taxes		15,826		14,226		8,902
	Domestic Production Activities allowance		—		—		567
	Other permanent differences		805		1,990		1,066
	Income tax expense	$	298,697	$	329,011	$	206,727
Components of net deferred tax liabilities
		December 31,
	(in thousands)	2014		2013
	Long-term:
	Assets:
	Stock compensation and other accrued amounts	$	26,527	$	24,815
	Net operating loss carryforward, net of valuation allowance		218,584		207,282
	Credit carryforward		4,068		4,068
			249,179		236,165
	Liabilities:
	Property, plant and equipment		-2,003,885		-1,696,006
	Net, long-term deferred tax liability		-1,754,706		-1,459,841
	Current:
	Assets:
	Other accrued amounts		13,475		16,854
			13,475		16,854
	Net deferred tax liabilities	$	-1,741,231	$	-1,442,987

COMMITMENTS_AND_CONTINGENCIES_

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies
Schedule of future minimum payments required under leases
	(in thousands)	Operating
		Leases
	2015	$	10,166
	2016		11,261
	2017		10,789
	2018		10,416
	2019		10,522
	Later years		67,795
	Total future minimum lease payments	$	120,949

SUPPLEMENTAL_DISCLOSURE_OF_CAS1

SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2014
Supplemental Disclosure of Cash Flow Information:
Supplemental Disclosure of Cash Flow Information
		Years Ended December 31,
	(in thousands)	2014		2013		2012
	Cash paid during the period for:
	Interest expense (including capitalized amounts)	$	66,167	$	50,754	$	42,420
	Interest capitalized	$	32,623	$	29,098	$	30,255
	Income taxes	$	354	$	205	$	377
	Cash received for income taxes	$	460	$	966	$	49,754

BASIS_OF_PRESENTATION_AND_SUMM2

BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) (USD $)	12 Months Ended
	Dec. 31, 2014
	segment
Number of reportable segments	1
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	8.00%
Oil, Gas and NGL Sales
Residue gas and NGLs, portion reflected in prices (as a percent)	100.00%
Increase in total revenue and processing costs	$51,400,000
Maximum [Member]
Fixed assets, net
Fixed assets expected lives	30 years
Minimum [Member]
Fixed assets, net
Fixed assets expected lives	3 years

LONGTERM_DEBT_Summary_Details

LONG-TERM DEBT - Summary (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Apr. 30, 2012	Jun. 30, 2014
In Thousands, unless otherwise specified
Debt Instrument
Long-term debt	$1,500,000	$924,000
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%
Notes 4.375 Percent [Member]
Debt Instrument
Long-term debt	$750,000			$750,000
Interest rate (as a percent)	4.38%			4.38%

LONGTERM_DEBT_Details

LONG-TERM DEBT (Details) (USD $)	12 Months Ended	1 Months Ended	8 Months Ended	12 Months Ended	3 Months Ended	1 Months Ended
	Dec. 31, 2012	31-May-14	Dec. 31, 2014	Dec. 31, 2014	Jun. 30, 2012	Apr. 30, 2012	Jun. 30, 2014	Dec. 31, 2013	Apr. 30, 2014
Debt Instrument
Long-term debt			$1,500,000,000	$1,500,000,000				$924,000,000
Loss on early extinguishment of debt	16,214,000
Line of Credit [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	1,000,000,000
Long-term debt								174,000,000
Letters of credit outstanding under the credit facility			2,500,000	2,500,000
Unused borrowing availability			997,500,000	997,500,000
Additional interest rate margin, low end of range (as a percent)			0.50%
Maximum leverage ratio				3.5
Line of Credit [Member] | Minimum [Member]
Debt Instrument
Current ratio to be maintained under credit facility				1
Line of Credit [Member] | Maximum [Member]
Debt Instrument
Additional interest rate margin, high end of range (as a percent)			1.25%
Notes 7.125 Percent [Member]
Debt Instrument
Interest rate (as a percent)					7.13%	7.13%
Loss on early extinguishment of debt					16,200,000
Notes 5.875 Percent [Member]
Debt Instrument
Long-term debt			750,000,000	750,000,000		750,000,000		750,000,000
Interest rate (as a percent)			5.88%	5.88%		5.88%		5.88%
Issuance of senior unsecured notes						737,000,000
Notes 4.375 Percent [Member]
Debt Instrument
Long-term debt			750,000,000	750,000,000			750,000,000
Interest rate (as a percent)			4.38%	4.38%			4.38%
Issuance of senior unsecured notes							$740,900,000
London Interbank Offered Rate (LIBOR) [Member] | Line of Credit [Member] | Minimum [Member]
Debt Instrument
Interest rate margin (as a percent)			1.50%
London Interbank Offered Rate (LIBOR) [Member] | Line of Credit [Member] | Maximum [Member]
Debt Instrument
Interest rate margin (as a percent)			2.25%
Debt Instrument Variable Rate Federal Funds [Member] | Line of Credit [Member]
Debt Instrument
Interest rate margin (as a percent)			0.50%
Debt Instrument Variable Rate Base One Month Adjusted LIBOR [Member] | Line of Credit [Member]
Debt Instrument
Interest rate margin (as a percent)			1.00%

PROPERTY_SALES_AND_ACQUISITION1

PROPERTY SALES AND ACQUISITIONS - Sales (Details) (USD $)	12 Months Ended			3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2013
Property Sales
Sales of other assets	$8,413,000	$31,661,000	$1,060,000
Triple Crown Gas Gathering and Processing System [Member]
Property Sales
Sales of other assets				31,000,000
Interest sold in property (as a percent)				50.00%
Non Core Oil and Gas Properties [Member]
Property Sales
Sale of interests in oil and gas properties	446,100,000	61,500,000	306,000,000
Texas [Member]
Property Sales
Sale of interests in oil and gas properties			$290,000,000

PROPERTY_SALES_AND_ACQUISITION2

PROPERTY SALES AND ACQUISITIONS - Acquisitions (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property Acquisitions and Sales
Acquisition of interest in oil and gas properties	$249.70	$37.10	$33.50

FAIR_VALUE_MEASUREMENTS_Detail

FAIR VALUE MEASUREMENTS (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2014	Apr. 30, 2012	Jun. 30, 2014
In Thousands, unless otherwise specified
Financial Assets (Liabilities):
Derivative instruments	$4,268
Derivative instruments - liabilities	-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, Level 1 [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%		4.38%
Notes 4.375 Percent [Member] | Fair Value, Inputs, Level 1 [Member]
Financial Assets (Liabilities):
Interest rate (as a percent)		4.38%
Reported Value Measurement [Member]
Financial Assets (Liabilities):
Derivative instruments	4,268
Derivative instruments - liabilities	-389
Reported Value Measurement [Member] | Notes 5.875 Percent [Member]
Financial Assets (Liabilities):
Long-term debt	-750,000	-750,000
Reported Value Measurement [Member] | Line of Credit [Member]
Financial Assets (Liabilities):
Long-term debt	-174,000
Reported Value Measurement [Member] | Notes 4.375 Percent [Member]
Financial Assets (Liabilities):
Long-term debt		-750,000
Estimate of Fair Value Measurement [Member]
Financial Assets (Liabilities):
Derivative instruments	4,268
Derivative instruments - liabilities	-389
Estimate of Fair Value Measurement [Member] | Notes 5.875 Percent [Member]
Financial Assets (Liabilities):
Long-term debt	-799,988	-776,250
Estimate of Fair Value Measurement [Member] | Line of Credit [Member]
Financial Assets (Liabilities):
Long-term debt	-174,000
Estimate of Fair Value Measurement [Member] | Notes 4.375 Percent [Member]
Financial Assets (Liabilities):
Long-term debt		-720,000

FAIR_VALUE_MEASUREMENTS_Other_

FAIR VALUE MEASUREMENTS - Other instruments (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Other Financial Instruments
Liabilities representing checks issued but not yet presented for payment	$42	$43.70
Accrued payroll related general and administrative expenses	44.2	41.9
Allowance for Trade Receivables [Member]
Other Financial Instruments
Aggregate allowance for doubtful accounts	$1.50	$6

FAIR_VALUE_MEASUREMENTS_Concen

FAIR VALUE MEASUREMENTS - Concentration (Details) (Sales Revenue, Goods, Net [Member])	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Enterprise Products
Concentration Risk
Percentage of sales to revenue, major customers (as a percent)	19.00%	24.00%
Sunoco Logistics
Concentration Risk
Percentage of sales to revenue, major customers (as a percent)	19.00%	22.00%
Oneok
Concentration Risk
Percentage of sales to revenue, major customers (as a percent)	10.00%

DERIVATIVE_INSTRUMENTSHEDGING_1

DERIVATIVE INSTRUMENTS/HEDGING (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Gain (loss) on derivative instruments, net
Gain (loss) on derivative instruments, net	$3,762	($209)	$245
Gains (losses) from settlement of derivative instruments:
Settlement gains (losses)	7,641	-4,088
Not Designated as Hedging Instrument [Member]
Gain (loss) on derivative instruments, net
Gain (loss) on derivative instruments, net	3,762	-209	245
Gains (losses) from settlement of derivative instruments:
Settlement gains (losses)	$7,641	($4,088)

DERIVATIVE_INSTRUMENTSHEDGING_2

DERIVATIVE INSTRUMENTS/HEDGING - Fair value (Details) (USD $)	Dec. 31, 2013
In Thousands, unless otherwise specified
Asset
Total gross amounts presented in accompanying balance sheet	$4,268
Liability
Total gross amounts presented in accompanying balance sheet	389
Not Designated as Hedging Instrument [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	389
Less: gross amounts not offset in the accompanying balance sheet	-389
Not Designated as Hedging Instrument [Member] | Oil Contracts [Member] | Other Current Assets [Member]
Asset
Total gross amounts presented in accompanying balance sheet	1,805
Not Designated as Hedging Instrument [Member] | Oil Contracts [Member] | Other Current Liabilities [Member]
Liability
Total gross amounts presented in accompanying balance sheet	389
Not Designated as Hedging Instrument [Member] | Natural Gas Contracts [Member] | Other Current Assets [Member]
Asset
Total gross amounts presented in accompanying balance sheet	$2,463

CAPITAL_STOCK_Details

CAPITAL STOCK (Details) (USD $)	1 Months Ended		12 Months Ended
In Thousands, except Share data, unless otherwise specified	Feb. 28, 2014	Feb. 28, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
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
Dividends
Cash dividend declared (in dollars per share)	$0.16	$0.14
Dividend payable
Dividend declared			$55,664	$48,423	$41,318
Dividend per share			$0.64	$0.56	$0.48

STOCKBASED_and_OTHER_COMPENSAT2

STOCK-BASED and OTHER COMPENSATION (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Options, Restricted Stock and Unit Awards
Compensation expense before capitalized cost	$28,805,000	$26,268,000	$34,186,000
Less amounts capitalized to oil and gas properties	-13,804,000	-11,989,000	-12,267,000
Compensation expense	15,001,000	14,279,000	21,919,000
Maximum number of shares of common stock that may be issued under the Stock Incentive Plan	6,600,000
Restricted Stock and Units [Member]
Options, Restricted Stock and Unit Awards
Compensation expense before capitalized cost	25,748,000	23,123,000	31,297,000
Restricted Stock [Member]
Options, Restricted Stock and Unit Awards
Restricted stock granted (in shares)	486,843	579,236	562,269
Restricted stock granted, weighted average grant-date fair value (in dollars per share)	$101.95	$75.39	$49.05
Performance Based Restricted Stock [Member]
Options, Restricted Stock and Unit Awards
Compensation expense before capitalized cost	12,141,000	11,105,000	19,066,000
Accelerated compensation cost			3,900,000
Compensation cost lower than 2012 costs due to the timing of awards granted		4,300,000
Restricted stock granted (in shares)	316,441	298,000	262,770
Restricted stock granted, weighted average grant-date fair value (in dollars per share)	$83.22	$77.75	$43.22
Vesting period	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	13,607,000	12,018,000	12,231,000
Restricted stock granted (in shares)	170,402	281,236	299,499
Restricted stock granted, weighted average grant-date fair value (in dollars per share)	$136.72	$72.89	$54.17
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	$3,057,000	$3,145,000	$2,889,000
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_and_OTHER_COMPENSAT3

STOCK-BASED and OTHER COMPENSATION - RSU activity (Details) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restricted Stock [Member]
Restricted stock and unit activity
Granted (in shares)	486,843	579,236	562,269
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Granted	$101.95	$75.39	$49.05
Fair value of resticted stock vested	$34.10	$25.70	$36
Performance Based Restricted Stock [Member]
Restricted stock and unit activity
Outstanding at the beginning of the period (in shares)	828,802
Vested (in shares)	-195,664
Granted (in shares)	316,441	298,000	262,770
Canceled (in shares)	-72,368
Outstanding at the end of the period (in shares)	877,211	828,802
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding beginning of period	$65.27
Vested	$73.01
Granted	$83.22	$77.75	$43.22
Canceled	$73.01
Outstanding end of period	$69.38	$65.27
Service Based Restricted Stock [Member]
Restricted stock and unit activity
Outstanding at the beginning of the period (in shares)	1,035,032
Vested (in shares)	-106,817
Granted (in shares)	170,402	281,236	299,499
Canceled (in shares)	-62,200
Outstanding at the end of the period (in shares)	1,036,417	1,035,032
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Outstanding beginning of period	$68.41
Vested	$37.91
Granted	$136.72	$72.89	$54.17
Canceled	$69.91
Outstanding end of period	$82.69	$68.41
Restricted Stock Units (RSUs) [Member]
Restricted stock and unit activity
Outstanding at the end of the period (in shares)	8,838	8,838

STOCKBASED_and_OTHER_COMPENSAT4

STOCK-BASED and OTHER COMPENSATION - Options, assumptions (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Assumptions used to determine the fair market value of options
Annual costs related to the plan	$11,000,000	$9,000,000	$8,200,000
Restricted Stock and Units [Member]
Options, Restricted Stock and Unit Awards
Unrecognized compensation costs related to unvested awards (in dollars)	83,900,000
Expected period to recognize unamortized compensation costs related to unvested awards	2 years 2 months 12 days
Restricted Stock Units (RSUs) [Member]
Options, Restricted Stock and Unit Awards
Share Based Compensation Arrangement by Share Based Payment Award, Equity Instruments Other than Options, Outstanding, Number	8,838	8,838
Employee Stock Option [Member]
Options, Restricted Stock and Unit Awards
Unrecognized compensation costs related to unvested awards (in dollars)		4,100,000
Expected period to recognize unamortized compensation costs related to unvested awards	1 year 9 months 18 days
Outstanding Stock Options
Outstanding balance at beginning of period (in shares)	531,016
Granted (in shares)	82,500	144,400	152,800
Exercised (in shares)	-211,258	-276,069	-558,419
Forfeited (in shares)	-18,176
Outstanding balance at end of period (in shares)	384,082	531,016
Exercisable at end of period (in shares)	178,926
Weighted Average Exercise Price
Outstanding balance at beginning of period (in dollars per share)	$59.78
Granted (in dollars per share)	$139.02	$72.25	$51.92
Exercised (in dollars per share)	$56.32
Forfeited (in dollars per share)	$70.67
Outstanding at end of period (in dollars per share)	$78.19	$59.78
Exercisable at end of period (in dollars per share)	$59.19
Weighted Average Remaining Term
Weighted Average Remaining Term, Outstanding at end of period	5 years
Weighted Average Remaining Term, Exercisable at end of period	4 years 1 month 6 days
Aggregate Intrinsic Value
Aggregate Intrinsic Value Outstanding at end of period (in dollars)	13,260,000
Aggregate Intrinsic Value Exercisable at the end of the period (in dollars)	8,319,000
Grant-Date Fair value
Number of options exercised (in shares)	211,258	276,069	558,419
Cash received from option exercises	11,899,000	14,494,000	11,433,000
Tax benefit from option exercises included in paid-in-capital			76,000
Intrinsic value of stock options exercised	15,384,000	10,109,000	22,482,000
Grant date fair value of options vested	4,419,000	2,521,000	2,560,000
Granted (in dollars per share)	$41.69	$21.64	$20.55
Non-vested Stock Options
Non-vested at the beginning of the period (in shares)	343,014
Granted (in shares)	82,500	144,400	152,800
Vested (in shares)	-202,182
Forfeited (in shares)	-18,176
Non-vested at the end of the period (in shares)	205,156	343,014
Weighted Average Grant Date Fair Value - Non-Vested Stock Options
Non-vested as of January (in dollars per share)	$21.64
Granted (in dollars per share)	$41.69	$21.64	$20.55
Vested (in dollars per share)	$21.86
Forfeited (in dollars per share)	$23.24
Non-vested as of December (in dollars per share)	$29.35	$21.64
Weighted Average Exercise Price - Non-Vested Stock Options
Non-vested at the beginning of the period (in dollars per share)	$63.81
Granted (in dollars per share)	$139.02
Vested (in dollars per share)	$62.48
Forfeited (in dollars per share)	$70.67
Non-vested at the end of the period (in dollars per share)	$94.76	$63.81
Assumptions used to determine the fair market value of options
Granted (in shares)	82,500	144,400	152,800
Weighted average grant-date fair value	$41.69	$21.64	$20.55
Weighted average exercise price	$139.02	$72.25	$51.92
Total fair value of options granted	$3,439,000	$3,125,000	$3,140,000
Expected years until exercise	4 years	4 years	5 years 3 months 18 days
Expected stock volatility (as a percent)	36.70%	38.60%	47.40%
Dividend yield (as a percent)	0.50%	0.80%	0.90%
Risk-free interest rate (as a percent)	1.80%	1.40%	0.60%
Maximum [Member] | Employee Stock Option [Member]
Grant-Date Fair value
Vesting period	5 years
Term of options from grant to expiration	10 years
Minimum [Member] | Employee Stock Option [Member]
Grant-Date Fair value
Vesting period	3 years
Term of options from grant to expiration	7 years

EARNINGS_PER_SHARE_Details

EARNINGS PER SHARE (Details) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Basic:
Net income	$507,204	$564,689	$353,823
Participating securities' share in earnings (in dollars)	-9,906	-11,091	-6,753
Net income applicable to common shareholders	497,298	553,598	347,070
Diluted:
Net income	507,204	564,689	353,823
Participating securities' share in earnings (in dollars)	-9,891	-11,076	-6,732
Net income applicable to common shareholders	$497,313	$553,613	$347,091
Shares:
Basic shares outstanding	85,679	85,288	84,757
Incremental shares from assumed exercise of stock options	131	121	277
Fully diluted common stock (in shares)	85,810	85,409	85,034
Excluded antidilutive securities (in shares)	94	251	414
Earnings per share to common shareholders
Basic (in dollars per share)	$5.79	$6.48	$4.08
Diluted (in dollars per share)	$5.78	$6.47	$4.07

ASSET_RETIREMENT_OBLIGATIONS_D

ASSET RETIREMENT OBLIGATIONS (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Asset Retirement Obligations
Balance at beginning of year	$154,026,000	$185,138,000
Liabilities incurred	13,015,000	5,547,000
Liability settlements and disposals	-27,036,000	-47,842,000
Accretion expense	7,583,000	7,871,000
Revisions of estimated liabilities	25,420,000	3,312,000
Balance at end of year	173,008,000	154,026,000
Less current obligation	13,216,000	27,058,000
Long-term asset retirement obligation	159,792,000	126,968,000
Liability settlements and disposals related to properties that were sold	$11,200,000	$4,400,000

INCOME_TAXES_Details

INCOME TAXES (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current Taxes:
Federal (benefit)		($381,000)	($1,629,000)
State (benefit)	404,000	-308,000	140,000
Current benefit	404,000	-689,000	-1,489,000
Deferred Taxes:
Federal	282,729,000	315,165,000	199,459,000
State	15,564,000	14,535,000	8,757,000
Deferred taxes	298,293,000	329,700,000	208,216,000
Total income tax expense (benefits)	298,697,000	329,011,000	206,727,000
U.S. statutory rate (as a percent)	35.00%	35.00%	35.00%
Reconciliations of the income tax (benefit) expense
Provision at statutory rate	282,066,000	312,795,000	196,192,000
Effect of state taxes	15,826,000	14,226,000	8,902,000
Domestic Production Activities allowance			567,000
Other permanent differences	805,000	1,990,000	1,066,000
Income Tax Expense (Benefit)	298,697,000	329,011,000	206,727,000
Long-term Assets:
Stock compensation and other accrued amounts	26,527,000	24,815,000
Net operating loss carryforward, net of valuation allowance	218,584,000	207,282,000
Credit carryforward	4,068,000	4,068,000
Net deferred tax assets, long-term	249,179,000	236,165,000
Long-term Liabilities:
Property, plant and equipment	-2,003,885,000	-1,696,006,000
Net, long-term deferred tax liability	-1,754,706,000	-1,459,841,000
Current Assets:
Other accrued amounts	13,475,000	16,854,000
Net deferred tax assets, current, total	13,475,000	16,854,000
Net deferred tax liabilities	-1,741,231,000	-1,442,987,000
U.S. net tax operating loss carryforward	651,100,000
U.S. net tax operating loss carryforward recorded to equity when utilized to reduce taxes payable	83,100,000
Valuation allowance against net operating losses	19,100,000
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

Recovered_Sheet1

Commitments and Contingencies - leases, etc. (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Commitments and Contingencies
Rental expense	$14,300,000	$13,200,000	$5,700,000
Future minimum payments under leases
2015	10,166,000
2016	11,261,000
2017	10,789,000
2018	10,416,000
2019	10,522,000
Later years	67,795,000
Total future minimum lease payments	$120,949,000

COMMITMENTS_AND_CONTINGENCIES_1

COMMITMENTS AND CONTINGENCIES - Purchases (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
Drilling Commitments [Member]
Construction, Drilling and Purchase Commitments
Commitments for purchases and other expenditures	$207.70
Gathering Facilities and Pipelines Commitments [Member]
Construction, Drilling and Purchase Commitments
Commitments for purchases and other expenditures	6.9
Commitments to Secure Use of Drilling Rigs [Member]
Construction, Drilling and Purchase Commitments
Commitments for purchases and other expenditures	$51.70

COMMITMENTS_AND_CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES - Delivery, leases (Details) (Natural Gas Sales Contracts [Member], USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014
	MMcf
Natural Gas Sales Contracts [Member]
Delivery Commitments
Volume of gas deliverable (in Bcf)	30,800
Delivery term	12 months
Financial commitment upon nondelivery	$91.70

COMMITMENTS_AND_CONTINGENCIES_3

COMMITMENTS AND CONTINGENCIES - Loss (Details) (USD $)	3 Months Ended	0 Months Ended			12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2012	Apr. 01, 2014	Dec. 31, 2013	Dec. 13, 2013	Dec. 31, 2008
Hitch Enterprises Case [Member]
Loss Contingencies
Accrued litigation expense	$16.40
Helmerich and Payne Case [Member]
Loss Contingencies
Accrued litigation expense					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

RELATED_PARTY_TRANSACTIONS_Det

RELATED PARTY TRANSACTIONS (Details) (USD $)	12 Months Ended			5 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	31-May-14
Helmerich and Payne, Inc [Member]
Related Party Transactions
Contract drilling services costs	$18.40	$17	$20.80
Subsidiary of Newpark Resources, Inc [Member]
Related Party Transactions
Contract drilling services costs		$3.50	$4.10	$0.60

SUPPLEMENTAL_DISCLOSURE_OF_CAS2

SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash paid during the period for:
Interest expense (including capitalized amounts)	$66,167	$50,754	$42,420
Interest capitalized	32,623	29,098	30,255
Income taxes	354	205	377
Cash received for income taxes	$460	$966	$49,754