Coterra Energy (CTRA) 10-Q 27 Apr 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 25, 2018
Document and Entity Information
Entity Registrant Name	CABOT OIL & GAS CORP
Entity Central Index Key	858,470
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding		451,487,754
Entity Current Reporting Status	Yes

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEET (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 964,928	$ 480,047
Accounts receivable, net	170,000	216,004
Income taxes receivable	81,420	56,666
Inventories	12,448	8,006
Derivative instruments	5,551	0
Current assets held for sale	0	1,440
Other current assets	1,771	2,794
Total current assets	1,236,118	764,957
Properties and equipment, net (Successful efforts method)	3,146,252	3,072,204
Equity method investments	120,501	86,077
Assets held for sale	6,807	778,855
Derivative instruments	5,762	2,239
Other assets	22,961	23,012
TOTAL ASSETS	4,538,401	4,727,344
Current liabilities
Accounts payable	174,662	238,045
Current portion of long-term debt	304,000	304,000
Accrued liabilities	11,570	27,441
Interest payable	12,257	27,575
Derivative instruments	8,002	30,637
Current liabilities held for sale	0	2,352
Total current liabilities	510,491	630,050
Long-term debt, net	1,218,231	1,217,891
Deferred income taxes	291,280	227,030
Asset retirement obligations	45,507	43,601
Liabilities held for sale	1,867	15,748
Postretirement benefits	29,722	29,396
Other liabilities	34,787	39,723
Total liabilities	2,131,885	2,203,439
Commitments and contingencies
Stockholders' equity
Common stock: Authorized - 960,000,000 shares of $0.10 par value in 2017 and 2016 Issued - 475,443,335 shares and 475,042,692 shares in 2017 and 2016, respectively	47,608	47,555
Additional paid-in capital	1,742,668	1,742,419
Retained earnings	1,251,568	1,162,430
Accumulated other comprehensive income (loss)	2,383	2,077
Less treasury stock, at cost: 12,935,926 and 9,892,680 shares in 2017 and 2016, respectively	(637,711)	(430,576)
Total stockholders' equity	2,406,516	2,523,905
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	4,538,401	4,727,344
Income taxes payable	$ 109	$ 0

CONDENSED CONSOLIDATED BALANCE3

CONDENSED CONSOLIDATED BALANCE SHEET (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Common stock, authorized (shares)	960,000,000	960,000,000
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, issued (shares)	476,081,339	475,547,419
Treasury stock (shares)	23,263,707	14,935,926

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENT OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
OPERATING REVENUES
Natural gas	$ 412,108	$ 433,442
Crude oil and condensate	48,722	42,990
Gain on derivative instruments	5,577	33,384
Brokered natural gas	4,950	4,695
Other	1,870	3,332
TOTAL OPERATING REVENUES	473,227	517,843
OPERATING EXPENSES
Direct operations	20,070	24,641
Transportation and gathering	112,125	123,474
Brokered natural gas	4,950	4,046
Taxes other than income	7,190	9,058
Exploration	3,617	6,198
Depreciation, depletion and amortization	82,128	135,100
General and administrative	24,060	23,700
TOTAL OPERATING EXPENSES	254,140	326,217
Loss on equity method investments	(994)	(1,283)
Loss on sale of assets	(41,049)	(223)
INCOME FROM OPERATIONS	177,044	190,120
Interest expense, net	20,058	20,771
Other expense	114	424
Income before income taxes	156,872	168,925
Income tax expense	39,641	63,205
NET INCOME	$ 117,231	$ 105,720
Earnings per share
Basic (in dollars per share)	$ 0.26	$ 0.23
Diluted (in dollars per share)	$ 0.25	$ 0.23
Weighted-average common shares outstanding
Basic (in shares)	459,715	465,348
Diluted (in shares)	461,549	466,888
Dividends per common share (in dollars per share)	$ 0.06	$ 0.02

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 117,231	$ 105,720
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation, depletion and amortization	82,128	135,100
Deferred income tax expense	64,287	53,289
Loss on sale of assets	41,049	223
Exploratory dry hole cost	(60)	2,842
Gain on derivative instruments	(5,577)	(33,384)
Net cash paid in settlement of derivative instruments	(26,131)	(1,524)
Loss on equity method investments	994	1,283
Amortization of debt issuance costs	1,195	1,189
Stock-based compensation and other	5,184	8,283
Changes in assets and liabilities:
Accounts receivable, net	50,216	(1,738)
Income taxes	(24,646)	10,534
Inventories	(4,309)	1,209
Other current assets	1,023	1,170
Accounts payable and accrued liabilities	(14,169)	151
Interest payable	(15,318)	(15,388)
Other assets and liabilities	(337)	419
Net cash provided by operating activities	272,760	269,378
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(156,257)	(208,384)
Proceeds from sale of assets	646,545	374
Investment in equity method investments	(35,418)	(7,742)
Net cash provided by (used in) investing activities	454,870	(215,752)
CASH FLOWS FROM FINANCING ACTIVITIES
Treasury stock repurchases	(207,134)	0
Dividends paid	(27,647)	(9,306)
Tax withholdings on vesting of stock awards	(7,968)	(5,414)
Other	0	37
Net cash used in financing activities	(242,749)	(14,683)
Net increase in cash and cash equivalents	484,881	38,943
Cash and cash equivalents, beginning of period	480,047	498,542
Cash and cash equivalents, end of period	$ 964,928	$ 537,485

Financial Statement Presentatio

Financial Statement Presentation	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Financial Statement Presentation	Financial Statement Presentation During interim periods, Cabot Oil & Gas Corporation (the Company) follows the same accounting policies disclosed in its Annual Report on Form 10-K/A for the year ended December 31, 2017 (Form 10-K/A) filed with the Securities and Exchange Commission (SEC). The interim financial statements should be read in conjunction with the notes to the consolidated financial statements and information presented in the Form 10-K/A. In management’s opinion, the accompanying interim condensed consolidated financial statements contain all material adjustments, consisting only of normal recurring adjustments, necessary for a fair statement. The results for any interim period are not necessarily indicative of the expected results for the entire year. Certain reclassifications have been made to prior year statements to conform with the current year presentation. These reclassifications had no impact on previously reported stockholders' equity, net income or cash flows. Recently Adopted Accounting Pronouncements Revenue Recognition. In May 2014, the Financial Accounting Standards Boards (FASB) issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers (Topic 606) (Accounting Standards Codification (ASC) 606, as subsequently amended). ASC 606 supersedes the revenue recognition requirements in Topic 605 Revenue Recognition (ASC 605), and requires entities to recognize revenue when control of the promised goods or services is transferred to customers at an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. The Company adopted ASC 606 as of January 1, 2018 using the modified retrospective transition method. The adoption of ASC 606 also included the adoption and modification of other guidance, particularly the creation of ASC 340-40 on costs to obtain or fulfill contracts with customers and ASC 610-20 on gains or losses on derecognition of nonfinancial assets. ASC 340-40 provides additional capitalization, amortization and impairment guidance for certain costs associated with obtaining or fulfilling contracts subject to ASC 606. ASC 610-20 provides guidance on the measurement and recognition of gains and losses for disposals of assets that are not the outputs of ordinary activities, such as sales of fixed assets, when they are not businesses or deconsolidation of subsidiaries. The guidance in ASC 610-20 largely aligns with the guidance in ASC 606. It also supersedes most guidance on real estate sales that was contained in ASC 360-20; however, it does not apply to conveyances of oil and gas interests, which continue to be governed by guidance in ASC 932 for oil and gas extractive activities. There was no material effect from the adoption of ASC 340-40 or ASC 610-20 separate from those discussed from the adoption of ASC 606. Financial Instruments. In January 2016, the FASB issued ASU 2016-01, Financial Instruments - Overall, as an amendment to ASC Subtopic 825-10. The amendments in this update address certain aspects of recognition, measurement, presentation and disclosure of financial instruments. Among other items, this update will simplify the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment. When a qualitative assessment indicates that impairment exists, an entity is required to measure the investment at fair value. This impairment assessment reduces the complexity of the other-than-temporary impairment guidance that entities follow currently. The Company adopted ASU 2016-01 as of January 1, 2018. The adoption of this guidance did not have a material effect on the Company's financial position, results of operation or cash flows. Statement of Cash Flows. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230), which is intended to reduce diversity in practice in how certain transactions are classified in the statement of cash flows. The guidance addresses eight specific cash flow issues for which current accounting guidance is either unclear or does not include specific guidance. The Company adopted this guidance effective January 1, 2018. In conjunction with the adoption, the Company made an accounting policy election to classify distributions it receives from its equity method investees based on the nature of distributions approach in which distributions received are classified on the basis of the nature of the activity that generated the distribution as either a return on investment (cash inflows from operating activities) or a return of investment (cash inflows from investing activities). The adoption of this guidance did not have a material effect on the Company's financial position, results of operation or cash flows. Recently Issued Accounting Pronouncements Leases. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). The new lease guidance supersedes Topic 840. The core principle of the guidance is that entities should recognize the assets and liabilities that arise from leases. This ASU does not apply to leases to explore for or use minerals, oil, natural gas and similar nonregenerative resources, including the intangible right to explore for those natural resources and rights to use the land in which those natural resources are contained. The guidance is effective for interim and annual periods beginning after December 15, 2018. This ASU is to be adopted using a modified retrospective approach. The Company plans to adopt this guidance effective January 1, 2019 and is currently evaluating the effect that adopting this guidance will have on its financial position, results of operations or cash flows. Additionally, in January 2018, the FASB issued ASU No. 2018-01, Leases (Topic 842): Practical Expedient for Transition. The amendments in this update provide an optional transition to not evaluate existing or expired land easements that were not previously accounted for under current leases guidance in Topic 840. An entity that elects this practical expedient should evaluate new or modified land easements beginning at the date of adoption. An entity that does not elect this practical expedient should evaluate all existing or expired land easements in connection with the adoption of the new lease requirements in Topic 842 to assess whether they meet the definition of a lease. The Company is currently evaluating this guidance to determine whether or not to make use of this practical expedient. Revenue Recognition On January 1, 2018, the Company adopted ASC 606, Revenue from Contracts with Customers, and the related guidance in ASC 340-40 (the new revenue standard), and related guidance on gains and losses on derecognition of nonfinancial assets ASC 610-20, using the modified retrospective method applied to those contracts which were not completed as of January 1, 2018. Under the modified retrospective method, the Company recognizes the cumulative effect of initially applying the new revenue standard as an adjustment to the opening balance of retained earnings; however, no significant adjustment was required as a result of adopting the new revenue standard. Results for reporting periods beginning after January 1, 2018 are presented under the new revenue standard. The comparative information has not been restated and continues to be reported under the historic accounting standards in effect for those periods. The impact of the adoption of the new revenue standard is expected to be immaterial to the Company’s net income on an ongoing basis. The Company’s revenue is typically generated from contracts to sell natural gas, crude oil or NGLs produced from interests in oil and gas properties owned by the Company. Contracts for the sale of natural gas and crude oil are evidenced by (1) base contracts for the sale and purchase of natural gas or crude oil, which document the general terms and conditions for the sale, and (2) transaction confirmations, which document the terms of each specific sale. These contracts generally require the Company to deliver a specific amount of a commodity per day for a specified number of days at a price that is either fixed or variable. The transaction confirmations specify a delivery point which represents the point at which control of the product is transferred to the customer. These contracts frequently meet the definition of a derivative under ASC 815, and are accounted for as derivatives unless the Company elects to treat them as normal sales as permitted under that guidance. The Company typically elects to treat contracts to sell oil and gas production as normal sales, which are then accounted for as contracts with customers. The Company has determined that these contracts represent multiple performance obligations which are satisfied when control of the commodity transfers to the customer, typically through the delivery of the specified commodity to a designated delivery point. Revenue is measured based on consideration specified in the contract with the customer, and excludes any amounts collected on behalf of third parties. The Company recognizes revenue in the amount that reflects the consideration it expects to be entitled to in exchange for transferring control of those goods to the customer. The contract consideration in the Company’s variable price contracts are typically allocated to specific performance obligations in the contract according to the price stated in the contract. Amounts allocated in the Company’s fixed price contracts are based on the standalone selling price of those products in the context of long-term, fixed price contracts, which generally approximates the contract price. Payment is generally received one or two months after the sale has occurred. Gain or loss on derivative instruments is outside the scope of ASC 606 and is not considered revenue from contracts with customers subject to ASC 606. The Company may use financial or physical contracts accounted for as derivatives as economic hedges to manage price risk associated with normal sales, or in limited cases may use them for contracts the Company intends to physically settle but do not meet all of the criteria to be treated as normal sales. Taxes assessed by a governmental authority that are both imposed on and concurrent with a specific revenue-producing transaction, and that are collected by the Company from a customer, are excluded from revenue. Producer Gas Imbalances. The Company applies the sales method of accounting for natural gas revenue. Under this method, revenues are recognized based on the actual volume of natural gas sold to purchasers. Natural gas production operations may include joint owners who take more or less than the production volumes entitled to them on certain properties. Production volume is monitored to minimize these natural gas imbalances. Under this method, a natural gas imbalance liability is recorded if the Company's excess takes of natural gas exceed its estimated remaining proved developed reserves for these properties at the actual price realized upon the gas sale. A receivable is recognized only to the extent an imbalance cannot be recouped from the reserves in the underlying properties. The Company’s aggregate imbalance positions at March 31, 2018 and December 31, 2017 were not material. Brokered Natural Gas. Revenues and expenses related to brokered natural gas are reported gross as part of operating revenues and operating expenses in accordance with applicable accounting standards. The Company buys and sells natural gas utilizing separate purchase and sale transactions, typically with separate counterparties, whereby the Company and/or the counterparty obtains control of the natural gas purchased or sold. Disaggregation of Revenue. The following table presents revenues disaggregated by product: Three Months Ended March 31, (In thousands) 2018 2017 (1) OPERATING REVENUES Natural gas $ 412,108 $ 433,442 Crude oil and condensate 48,722 42,990 Brokered natural gas 4,950 4,695 Other 1,870 3,332 Total revenues from contracts with customers 467,650 484,459 Gain on derivative instruments 5,577 33,384 Total operating revenues $ 473,227 $ 517,843 _______________________________________________________________________________ (1) As noted above, prior period amounts have not been adjusted under the modified retrospective method. All of the Company’s revenues from contracts with customers represent products transferred at a point in time as control is transferred to the customer and are generated in the United States. Transaction Price Allocated to Remaining Performance Obligations. A significant number of the Company’s product sales are short-term in nature with a contract term of one year or less. For those contracts, the Company has utilized the practical expedient exempting the Company from disclosure of the transaction price allocated to remaining performance obligations if the performance obligation is part of a contract that has an original expected duration of one year or less. As of March 31, 2018 , the Company has $15.3 million of unsatisfied performance obligations related to natural gas sales that have a fixed pricing component and a contract term greater than one year. The Company expects to recognize these obligations over the next five years . Contract Balances. Receivables from contracts with customers are recorded when the right to consideration becomes unconditional, generally when control of the product has been transferred to the customer. Receivables from contracts with customers were $161.1 million and $215.5 million as of March 31, 2018 and December 31, 2017 , respectively, and are reported in accounts receivable, net on the Condensed Consolidated Balance Sheet. The Company currently has no assets or liabilities related to its revenue contracts, including no upfront or rights to deficiency payments. Practical Expedients. The Company has made use of certain practical expedients in adopting the new revenue standard, including the value of unsatisfied performance obligations are not disclosed for (i) contracts with an original expected length of one year or less, (ii) contracts for which the Company recognizes revenue at the amount to which the Company has the right to invoice, (iii) variable consideration which is allocated entirely to a wholly unsatisfied performance obligation and meets the variable allocation criteria in the standard and (iv) only contracts that are not completed at transition. The Company has not adjusted the promised amount of consideration for the effects of a significant financing component if the Company expects, at contract inception, that the period between when the Company transfers a promised good or service to the customer and when the customer pays for that good or service will be one year or less.

Properties and Equipment, Net

Properties and Equipment, Net	3 Months Ended
	Mar. 31, 2018
Property, Plant and Equipment [Abstract]
Properties and Equipment, Net	Properties and Equipment, Net Properties and equipment, net are comprised of the following: (In thousands) March 31, December 31, Proved oil and gas properties $ 5,082,995 $ 4,932,512 Unproved oil and gas properties 194,003 190,474 Gathering and pipeline systems 1,569 1,569 Land, building and other equipment 81,957 82,670 5,360,524 5,207,225 Accumulated depreciation, depletion and amortization (2,214,272 ) (2,135,021 ) $ 3,146,252 $ 3,072,204 At March 31, 2018 , the Company did not have any projects that had exploratory well costs capitalized for a period of greater than one year after drilling. Divestitures In February 2018, the Company sold its operated and non-operated Eagle Ford Shale assets for $765.0 million . During the fourth quarter of 2017, the Company classified these assets as held for sale and recorded an impairment charge of $414.3 million associated with the proposed sale of these properties. Upon closing the sale in the first quarter of 2018, the Company recognized a loss on sale of oil and gas properties of $44.8 million .

Equity Method Investments

Equity Method Investments	3 Months Ended
	Mar. 31, 2018
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	Equity Method Investments The Company holds a 25% equity interest in Constitution Pipeline Company, LLC (Constitution) and a 20% equity interest in Meade Pipeline Co LLC (Meade). Activity related to these equity method investments is as follows: Constitution Meade Total Three Months Ended March 31, (In thousands) 2018 2017 2018 2017 2018 2017 Balance at beginning of period $ 732 $ 96,850 $ 85,345 $ 32,674 $ 86,077 $ 129,524 Contributions 250 1,125 35,168 6,617 35,418 7,742 Loss on equity method investments (982 ) (1,282 ) (12 ) (1 ) (994 ) (1,283 ) Balance at end of period $ — $ 96,693 $ 120,501 $ 39,290 $ 120,501 $ 135,983 During 2018 , the Company expects to contribute approximately $60.0 million to its equity method investments. For further information regarding the Company’s equity method investments, refer to Note 4 of the Notes to the Consolidated Financial Statements in the Form 10-K/A. Constitution As of March 31, 2018, the Company’s carrying value of its investment in Constitution is less than its proportionate share of Constitution’s net assets by $95.9 million . This basis difference is due to the Company’s impairment recorded in the fourth quarter of 2017 and relates entirely to the pipeline assets of Constitution. The Company expects to amortize this basis difference once the related assets of Constitution are placed in service, which may or may not occur, depending on the outcome of the legal and regulatory process related to certain permitting matters. The Company remains committed to funding the project in an amount proportionate to its ownership interest for the development and construction of the new pipeline.

Debt and Credit Agreements

Debt and Credit Agreements	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Debt and Credit Agreements	Debt and Credit Agreements The Company’s debt and credit agreements consisted of the following: (In thousands) March 31, December 31, Total debt 6.51% weighted-average senior notes (1) $ 361,000 $ 361,000 9.78% senior notes (2) 67,000 67,000 5.58% weighted-average senior notes 175,000 175,000 3.65% weighted-average senior notes 925,000 925,000 Revolving credit facility — — Unamortized debt issuance costs (5,769 ) (6,109 ) $ 1,522,231 $ 1,521,891 _______________________________________________________________________________ (1) Includes $237.0 million of current portion of long-term debt at March 31, 2018 and December 31, 2017 , respectively. (2) Includes $67.0 million of current portion of long-term debt at March 31, 2018 and December 31, 2017 , respectively. The borrowing base under the terms of the Company's revolving credit facility is redetermined annually in April. In addition, either the Company or the banks may request an interim redetermination twice a year or in connection with certain acquisitions or divestitures of oil and gas properties. Effective April 18, 2018 , the borrowing base and available commitments were reaffirmed at $3.2 billion and $1.7 billion , respectively. At March 31, 2018 , the Company was in compliance with all restrictive financial covenants for both its revolving credit facility and senior notes. At March 31, 2018 , the Company had no borrowings outstanding under its revolving credit facility and had unused commitments of $1.7 billion .

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	3 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities As of March 31, 2018 , the Company had the following outstanding financial commodity derivatives: Basis Swaps Swaps Type of Contract Volume Contract Period Weighted-Average Weighted-Average Financial contracts Natural gas (Leidy) 26.7 Bcf Apr. 2018 - Dec. 2018 $ (0.69 ) Natural gas (Transco) 18.7 Bcf Apr. 2018 - Dec. 2019 $ 0.42 Natural gas (NYMEX) 69.5 Bcf Apr. 2018 - Dec. 2018 $ 2.93 Natural gas (NYMEX) 10.4 Bcf Apr. 2018 - Oct. 2018 $ 3.10 As of March 31, 2018 , the Company had the following outstanding physical commodity derivatives: Type of Contract Volume Contract Period Weighted-Average Fixed Price Physical contracts Natural gas purchase 10.4 Bcf Apr. 2018 - Oct. 2018 $ 3.67 In the tables above, natural gas prices are stated per Mcf. Effect of Derivative Instruments on the Condensed Consolidated Balance Sheet Derivative Assets Derivative Liabilities (In thousands) Balance Sheet Location March 31, December 31, March 31, December 31, Commodity contracts Derivative instruments (current) $ 5,551 $ — $ 8,002 $ 30,637 Commodity contracts Derivative instruments (non-current) 5,762 2,239 — — $ 11,313 $ 2,239 $ 8,002 $ 30,637 Offsetting of Derivative Assets and Liabilities in the Condensed Consolidated Balance Sheet (In thousands) March 31, December 31, Derivative assets Gross amounts of recognized assets $ 11,950 $ 2,239 Gross amounts offset in the statement of financial position (637 ) — Net amounts of assets presented in the statement of financial position 11,313 2,239 Gross amounts of financial instruments not offset in the statement of financial position 4,728 — Net amount $ 16,041 $ 2,239 Derivative liabilities Gross amounts of recognized liabilities $ 8,639 $ 30,637 Gross amounts offset in the statement of financial position (637 ) — Net amounts of liabilities presented in the statement of financial position 8,002 30,637 Gross amounts of financial instruments not offset in the statement of financial position 5,534 241 Net amount $ 13,536 $ 30,878 Effect of Derivative Instruments on the Condensed Consolidated Statement of Operations Three Months Ended (In thousands) 2018 2017 Cash received (paid) on settlement of derivative instruments Gain (loss) on derivative instruments $ (26,131 ) $ (1,524 ) Non-cash gain (loss) on derivative instruments Gain (loss) on derivative instruments 31,708 34,908 $ 5,577 $ 33,384

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company follows the authoritative guidance for measuring fair value of assets and liabilities in its financial statements. For further information regarding the fair value hierarchy, refer to Note 1 of the Notes to the Consolidated Financial Statements in the Form 10-K/A. Financial Assets and Liabilities The following fair value hierarchy table presents information about the Company’s financial assets and liabilities measured at fair value on a recurring basis: (In thousands) Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Balance at Assets Deferred compensation plan $ 15,717 $ — $ — $ 15,717 Derivative instruments — 3,326 7,987 11,313 Total assets $ 15,717 $ 3,326 $ 7,987 $ 27,030 Liabilities Deferred compensation plan $ 27,605 $ — $ — $ 27,605 Derivative instruments — — 8,002 8,002 Total liabilities $ 27,605 $ — $ 8,002 $ 35,607 (In thousands) Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Balance at Assets Deferred compensation plan $ 14,966 $ — $ — $ 14,966 Derivative instruments — — 2,239 2,239 Total assets $ 14,966 $ — $ 2,239 $ 17,205 Liabilities Deferred compensation plan $ 29,145 $ — $ — $ 29,145 Derivative instruments — — 30,637 30,637 Total liabilities $ 29,145 $ — $ 30,637 $ 59,782 The Company’s investments associated with its deferred compensation plan consist of mutual funds and deferred shares of the Company’s common stock that are publicly traded and for which market prices are readily available. The derivative instruments were measured based on quotes from the Company’s counterparties or internal models. Such quotes and models have been derived using an income approach that considers various inputs including current market and contractual prices for the underlying instruments, quoted forward prices for natural gas and crude oil, basis differentials, volatility factors and interest rates, such as a LIBOR curve for a similar length of time as the derivative contract term as applicable. Estimates are verified using relevant NYMEX futures contracts and/or are compared to multiple quotes obtained from counterparties for reasonableness. The determination of the fair values presented above also incorporates a credit adjustment for non-performance risk. The Company measured the non-performance risk of its counterparties by reviewing credit default swap spreads for the various financial institutions with which it has derivative transactions, while non-performance risk of the Company is evaluated using a market credit spread provided by the Company’s bank. The Company has not incurred any losses related to non-performance risk of its counterparties and does not anticipate any material impact on its financial results due to non-performance by third parties. The most significant unobservable inputs relative to the Company’s Level 3 derivative contracts are basis differentials and volatility factors. An increase (decrease) in these unobservable inputs would result in an increase (decrease) in fair value, respectively. The Company does not have access to the specific assumptions used in its counterparties’ valuation models. Consequently, additional disclosures regarding significant Level 3 unobservable inputs were not provided. The following table sets forth a reconciliation of changes in the fair value of financial assets and liabilities classified as Level 3 in the fair value hierarchy: Three Months Ended (In thousands) 2018 2017 Balance at beginning of period $ (28,398 ) $ (15,868 ) Total gain (loss) included in earnings 6,628 21,918 Settlement (gain) loss 21,755 (981 ) Transfers in and/or out of level 3 — — Balance at end of period $ (15 ) $ 5,069 Change in unrealized gains (losses) relating to assets and liabilities still held at the end of the period $ 2,217 $ 20,937 There were no transfers between Level 1 and Level 2 fair value measurements for the three months ended March 31, 2018 and 2017 . Non-Financial Assets and Liabilities The Company discloses or recognizes its non-financial assets and liabilities, such as impairments, at fair value on a nonrecurring basis. As none of the Company’s other non-financial assets and liabilities were measured at fair value as of March 31, 2018 , additional disclosures were not required. The estimated fair value of the Company’s asset retirement obligations at inception is determined by utilizing the income approach by applying a credit-adjusted risk-free rate, which takes into account the Company’s credit risk, the time value of money, and the current economic state to the undiscounted expected abandonment cash flows. Given the unobservable nature of the inputs, the measurement of the asset retirement obligations was classified as Level 3 in the fair value hierarchy. Fair Value of Other Financial Instruments The estimated fair value of other financial instruments is the amount at which the instrument could be exchanged currently between willing parties. The carrying amount reported in the Condensed Consolidated Balance Sheet for cash and cash equivalents approximates fair value due to the short-term maturities of these instruments. Cash and cash equivalents are classified as Level 1 in the fair value hierarchy and the remaining financial instruments are classified as Level 2. The Company uses available market data and valuation methodologies to estimate the fair value of debt. The fair value of debt is the estimated amount the Company would have to pay a third party to assume the debt, including a credit spread for the difference between the issue rate and the period end market rate. The credit spread is the Company’s default or repayment risk. The credit spread (premium or discount) is determined by comparing the Company’s senior notes and revolving credit facility to new issuances (secured and unsecured) and secondary trades of similar size and credit statistics for both public and private debt. The fair value of all senior notes and the revolving credit facility is based on interest rates currently available to the Company. The Company’s debt is valued using an income approach and classified as Level 3 in the fair value hierarchy. The carrying amount and fair value of debt is as follows: March 31, 2018 December 31, 2017 (In thousands) Carrying Amount Estimated Fair Value Carrying Amount Estimated Fair Value Long-term debt $ 1,522,231 $ 1,499,909 $ 1,521,891 $ 1,527,624 Current maturities (304,000 ) (308,846 ) (304,000 ) (312,055 ) Long-term debt, excluding current maturities $ 1,218,231 $ 1,191,063 $ 1,217,891 $ 1,215,569

Asset Retirement Obligations

Asset Retirement Obligations	3 Months Ended
	Mar. 31, 2018
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligations	Asset Retirement Obligations Activity related to the Company’s asset retirement obligations is as follows: (In thousands) Three Months Ended Balance at beginning of period (1) $ 48,553 Liabilities incurred 1,546 Liabilities settled (413 ) Liabilities divested (3,782 ) Accretion expense 603 Balance at end of period (2) $ 46,507 _______________________________________________________________________________ (1) Includes $5.0 million of current asset retirement obligations included in accrued liabilities at December 31, 2017 . (2) Includes $1.0 million of current asset retirement obligations included in accrued liabilities at March 31, 2018 .

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Contractual Obligations The Company has various contractual obligations in the normal course of its operations. There have been no material changes to the Company’s contractual obligations described under “Transportation and Gathering Agreements” and "Lease Commitments” as disclosed in Note 9 of the Notes to Consolidated Financial Statements in the Form 10-K/A. Legal Matters The Company is a defendant in various legal proceedings arising in the normal course of business. All known liabilities are accrued when management determines they are probable based on its best estimate of the potential loss. While the outcome and impact of these legal proceedings on the Company cannot be predicted with certainty, management believes that the resolution of these proceedings will not have a material effect on the Company’s financial position, results of operations or cash flows. Contingency Reserves. When deemed necessary, the Company establishes reserves for certain legal proceedings. The establishment of a reserve is based on an estimation process that includes the advice of legal counsel and subjective judgment of management. While management believes these reserves to be adequate, it is reasonably possible that the Company could incur additional losses with respect to those matters in which reserves have been established. The Company believes that any such amount above the amounts accrued would not be material to the Condensed Consolidated Financial Statements. Future changes in facts and circumstances not currently foreseeable could result in the actual liability exceeding the estimated ranges of loss and amounts accrued.

Capital Stock

Capital Stock	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Capital Stock	Capital Stock Treasury Stock In February 2018, the Board of Directors authorized an increase of 25.0 million shares to the Company’s share repurchase program. After this authorization, the total number of shares available for repurchase is 30.1 million shares. Under the share repurchase program, the Company may purchase shares of common stock in the open market or in negotiated transactions. The timing and amount of any stock purchases are determined at the discretion of management. The Company may use the repurchased shares to fund stock compensation programs currently in existence, or for other corporate purposes. All purchases executed to date have been through open market transactions. There is no expiration date associated with the authorization to repurchase common stock of the Company. During the first three months of 2018 , the Company repurchased 8.3 million shares for a total cost of $207.1 million . As of March 31, 2018 , 21.7 million shares are available for repurchase under the share repurchase program. No treasury shares have been delivered or sold by the Company subsequent to the repurchase. As of March 31, 2018 , 23.3 million shares were held as treasury stock. Subsequent Event. Subsequent to March 31, 2018 , the Company repurchased 1.6 million shares for a total cost of $38.5 million under a Rule 10b5-1 Plan. The plan expires on April 30, 2018.

Stock-based Compensation

Stock-based Compensation	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based Compensation	Stock-based Compensation General From time to time the Company grants certain stock-based compensation awards, including restricted stock awards, restricted stock units and performance share awards. Stock-based compensation expense associated with these awards was $5.4 million and $8.3 million in the first quarter of 2018 and 2017 , respectively. Stock-based compensation expense is included in general and administrative expense in the Condensed Consolidated Statement of Operations. Refer to Note 13 of the Notes to the Consolidated Financial Statements in the Form 10-K/A for further description of the various types of stock-based compensation awards and the applicable award terms. Restricted Stock Units During the first three months of 2018 , 71,400 restricted stock units were granted to non-employee directors of the Company with a weighted-average grant date value of $23.42 per unit. The fair value of these units is measured based on the closing stock price on grant date and compensation expense is recorded immediately. These units immediately vest and are issued when the director ceases to be a director of the Company. Performance Share Awards The performance period for the awards granted during the first three months of 2018 commenced on January 1, 2018 and ends on December 31, 2020 . The Company used an annual forfeiture rate assumption ranging from 0% to 5% for purposes of recognizing stock-based compensation expense for its performance share awards. Performance Share Awards Based on Internal Performance Metrics The fair value of performance share award grants based on internal performance metrics is based on the closing stock price on the grant date. Each performance share award represents the right to receive up to 100% of the award in shares of common stock. Based on the Company’s probability assessment at March 31, 2018 , it is considered probable that the criteria for all performance awards based on internal metrics awards will be met. Employee Performance Share Awards. During the first three months of 2018 , 531,670 Employee Performance Share Awards were granted at a grant date value of $23.25 per share. The performance metrics are set by the Company’s compensation committee and are based on the Company’s average production, average finding costs and average reserve replacement over a three -year performance period. Hybrid Performance Share Awards. During the first three months of 2018 , 321,720 Hybrid Performance Share Awards were granted at a grant date value of $23.25 per share. The 2018 awards vest 25% on each of the first and second anniversary dates and 50% on the third anniversary , provided that the Company has $100 million or more of operating cash flow for the year preceding the vesting date, as set by the Company’s compensation committee. If the Company does not meet the performance metric for the applicable period, then the portion of the performance shares that would have been issued on that anniversary date will be forfeited. Performance Share Awards Based on Market Conditions These awards have both an equity and liability component, with the right to receive up to the first 100% of the award in shares of common stock and the right to receive up to an additional 100% of the value of the award in excess of the equity component in cash. The equity portion of these awards is valued on the grant date and is not marked to market, while the liability portion of the awards is valued as of the end of each reporting period on a mark-to-market basis. The Company calculates the fair value of the equity and liability portions of the awards using a Monte Carlo simulation model. TSR Performance Share Awards. During the first three months of 2018 , 482,581 TSR Performance Share Awards were granted and are earned, or not earned, based on the comparative performance of the Company’s common stock measured against a predetermined group of companies in the Company’s peer group over a three -year performance period. The following assumptions were used to determine the grant date fair value of the equity component (February 21, 2018 ) and the period-end fair value of the liability component of the TSR Performance Share Awards: Grant Date March 31, 2018 Fair value per performance share award $ 19.92 $8.44-$17.09 Assumptions: Stock price volatility 37.3 % 26.0% - 38.1% Risk free rate of return 2.40 % 2.00% - 2.35%

Earnings per Common Share

Earnings per Common Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Earnings per Common Share	Earnings per Common Share Basic earnings per share (EPS) is computed by dividing net income by the weighted-average number of common shares outstanding for the period. Diluted EPS is similarly calculated except that the common shares outstanding for the period is increased using the treasury stock method to reflect the potential dilution that could occur if outstanding stock appreciation rights were exercised and stock awards were vested at the end of the applicable period. Anti-dilutive shares represent potentially dilutive securities that are excluded from the computation of diluted income or loss per share as their impact would be anti-dilutive. The following is a calculation of basic and diluted weighted-average shares outstanding: Three Months Ended (In thousands) 2018 2017 Weighted-average shares - basic 459,715 465,348 Dilution effect of stock appreciation rights and stock awards at end of period 1,834 1,540 Weighted-average shares - diluted 461,549 466,888 The following is a calculation of weighted-average shares excluded from diluted EPS due to the anti-dilutive effect: Three Months Ended (In thousands) 2018 2017 Weighted-average stock appreciation rights and stock awards excluded from diluted EPS due to the anti-dilutive effect calculated using the treasury stock method 608 477

Income Taxes (Notes)

Income Taxes (Notes)	3 Months Ended
	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes On December 22, 2017, the U.S. enacted tax legislation referred to as the Tax Cuts and Jobs Act (the Tax Act) which significantly changes U.S. corporate income tax laws beginning, generally, in 2018. These changes include, among others, (i) a permanent reduction of the U.S. corporate income tax rate from a top marginal rate of 35% to a flat rate of 21%, (ii) elimination of the corporate alternative minimum tax, (iii) immediate deductions for certain new investments instead of deductions for depreciation expense over time, (iv) limitation on the tax deduction for interest expense to 30% of adjusted taxable income, (v) limitation of the deduction for net operating losses to 80% of current year taxable income and elimination of net operating loss carrybacks, and (vi) elimination of many business deductions and credits, including the domestic production activities deduction, the deduction for entertainment expenditures, and the deduction for certain executive compensation in excess of $1 million. The Company included the impacts of the Tax Act in the fourth quarter 2017 consolidated financial statements, and no changes were made to those provisional amounts during the first quarter 2018. The Company will continue to examine the impact of this legislation and future regulations. Additional impacts from the enactment of the Tax Act will be recorded as they are identified during the measurement period as provided for in SAB No. 118, which extends up to one year from the enactment date. The first quarter 2018 tax provision reflects the law changes noted above, including the new corporate tax rate of 21%. Income tax expense decrease d $23.6 million due to a lower effective tax rate and slightly lower pre tax income. The effective tax rates for the first three months of 2018 and 2017 were 25.3% and 37.4% , respectively. The decrease in the effective tax rate is primarily due to the impact of the Tax Act law changes that were effective January 1, 2018, partially offset by an increase in the blended state statutory tax rate as a result of changes in the Company's state apportionment factors due to the Eagle Ford Shale asset divestiture in February 2018.

Additional Balance Sheet Inform

Additional Balance Sheet Information	3 Months Ended
	Mar. 31, 2018
Balance Sheet Related Disclosures [Abstract]
Additional Balance Sheet Information	Additional Balance Sheet Information Certain balance sheet amounts are comprised of the following: (In thousands) March 31, December 31, Accounts receivable, net Trade accounts $ 161,085 $ 215,511 Joint interest accounts 673 467 Other accounts 9,528 1,312 171,286 217,290 Allowance for doubtful accounts (1,286 ) (1,286 ) $ 170,000 $ 216,004 Other assets Deferred compensation plan $ 15,717 $ 14,966 Debt issuance costs 7,136 7,990 Other accounts 108 56 $ 22,961 $ 23,012 Accounts payable Trade accounts $ 19,858 $ 7,815 Natural gas purchases 3,468 4,299 Royalty and other owners 27,614 39,207 Accrued transportation 46,704 51,433 Accrued capital costs 42,162 31,130 Taxes other than income 20,087 16,801 Deposits received for asset sales 5,000 81,500 Other accounts 9,769 5,860 $ 174,662 $ 238,045 Accrued liabilities Employee benefits $ 8,431 $ 20,645 Taxes other than income 1,525 550 Income taxes payable 109 — Asset retirement obligations 1,000 4,952 Other accounts 505 1,294 $ 11,570 $ 27,441 Other liabilities Deferred compensation plan $ 27,605 $ 29,145 Other accounts 7,182 10,578 $ 34,787 $ 39,723

Financial Statement Presentat19

Financial Statement Presentation (Policies)	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Recent Accounting Pronouncements	Recently Adopted Accounting Pronouncements Revenue Recognition. In May 2014, the Financial Accounting Standards Boards (FASB) issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers (Topic 606) (Accounting Standards Codification (ASC) 606, as subsequently amended). ASC 606 supersedes the revenue recognition requirements in Topic 605 Revenue Recognition (ASC 605), and requires entities to recognize revenue when control of the promised goods or services is transferred to customers at an amount that reflects the consideration to which the entity expects to be entitled to in exchange for those goods or services. The Company adopted ASC 606 as of January 1, 2018 using the modified retrospective transition method. The adoption of ASC 606 also included the adoption and modification of other guidance, particularly the creation of ASC 340-40 on costs to obtain or fulfill contracts with customers and ASC 610-20 on gains or losses on derecognition of nonfinancial assets. ASC 340-40 provides additional capitalization, amortization and impairment guidance for certain costs associated with obtaining or fulfilling contracts subject to ASC 606. ASC 610-20 provides guidance on the measurement and recognition of gains and losses for disposals of assets that are not the outputs of ordinary activities, such as sales of fixed assets, when they are not businesses or deconsolidation of subsidiaries. The guidance in ASC 610-20 largely aligns with the guidance in ASC 606. It also supersedes most guidance on real estate sales that was contained in ASC 360-20; however, it does not apply to conveyances of oil and gas interests, which continue to be governed by guidance in ASC 932 for oil and gas extractive activities. There was no material effect from the adoption of ASC 340-40 or ASC 610-20 separate from those discussed from the adoption of ASC 606. Financial Instruments. In January 2016, the FASB issued ASU 2016-01, Financial Instruments - Overall, as an amendment to ASC Subtopic 825-10. The amendments in this update address certain aspects of recognition, measurement, presentation and disclosure of financial instruments. Among other items, this update will simplify the impairment assessment of equity investments without readily determinable fair values by requiring a qualitative assessment to identify impairment. When a qualitative assessment indicates that impairment exists, an entity is required to measure the investment at fair value. This impairment assessment reduces the complexity of the other-than-temporary impairment guidance that entities follow currently. The Company adopted ASU 2016-01 as of January 1, 2018. The adoption of this guidance did not have a material effect on the Company's financial position, results of operation or cash flows. Statement of Cash Flows. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230), which is intended to reduce diversity in practice in how certain transactions are classified in the statement of cash flows. The guidance addresses eight specific cash flow issues for which current accounting guidance is either unclear or does not include specific guidance. The Company adopted this guidance effective January 1, 2018. In conjunction with the adoption, the Company made an accounting policy election to classify distributions it receives from its equity method investees based on the nature of distributions approach in which distributions received are classified on the basis of the nature of the activity that generated the distribution as either a return on investment (cash inflows from operating activities) or a return of investment (cash inflows from investing activities). The adoption of this guidance did not have a material effect on the Company's financial position, results of operation or cash flows. Recently Issued Accounting Pronouncements Leases. In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). The new lease guidance supersedes Topic 840. The core principle of the guidance is that entities should recognize the assets and liabilities that arise from leases. This ASU does not apply to leases to explore for or use minerals, oil, natural gas and similar nonregenerative resources, including the intangible right to explore for those natural resources and rights to use the land in which those natural resources are contained. The guidance is effective for interim and annual periods beginning after December 15, 2018. This ASU is to be adopted using a modified retrospective approach. The Company plans to adopt this guidance effective January 1, 2019 and is currently evaluating the effect that adopting this guidance will have on its financial position, results of operations or cash flows. Additionally, in January 2018, the FASB issued ASU No. 2018-01, Leases (Topic 842): Practical Expedient for Transition. The amendments in this update provide an optional transition to not evaluate existing or expired land easements that were not previously accounted for under current leases guidance in Topic 840. An entity that elects this practical expedient should evaluate new or modified land easements beginning at the date of adoption. An entity that does not elect this practical expedient should evaluate all existing or expired land easements in connection with the adoption of the new lease requirements in Topic 842 to assess whether they meet the definition of a lease. The Company is currently evaluating this guidance to determine whether or not to make use of this practical expedient. Revenue Recognition On January 1, 2018, the Company adopted ASC 606, Revenue from Contracts with Customers, and the related guidance in ASC 340-40 (the new revenue standard), and related guidance on gains and losses on derecognition of nonfinancial assets ASC 610-20, using the modified retrospective method applied to those contracts which were not completed as of January 1, 2018. Under the modified retrospective method, the Company recognizes the cumulative effect of initially applying the new revenue standard as an adjustment to the opening balance of retained earnings; however, no significant adjustment was required as a result of adopting the new revenue standard. Results for reporting periods beginning after January 1, 2018 are presented under the new revenue standard. The comparative information has not been restated and continues to be reported under the historic accounting standards in effect for those periods. The impact of the adoption of the new revenue standard is expected to be immaterial to the Company’s net income on an ongoing basis. The Company’s revenue is typically generated from contracts to sell natural gas, crude oil or NGLs produced from interests in oil and gas properties owned by the Company. Contracts for the sale of natural gas and crude oil are evidenced by (1) base contracts for the sale and purchase of natural gas or crude oil, which document the general terms and conditions for the sale, and (2) transaction confirmations, which document the terms of each specific sale. These contracts generally require the Company to deliver a specific amount of a commodity per day for a specified number of days at a price that is either fixed or variable. The transaction confirmations specify a delivery point which represents the point at which control of the product is transferred to the customer. These contracts frequently meet the definition of a derivative under ASC 815, and are accounted for as derivatives unless the Company elects to treat them as normal sales as permitted under that guidance. The Company typically elects to treat contracts to sell oil and gas production as normal sales, which are then accounted for as contracts with customers. The Company has determined that these contracts represent multiple performance obligations which are satisfied when control of the commodity transfers to the customer, typically through the delivery of the specified commodity to a designated delivery point. Revenue is measured based on consideration specified in the contract with the customer, and excludes any amounts collected on behalf of third parties. The Company recognizes revenue in the amount that reflects the consideration it expects to be entitled to in exchange for transferring control of those goods to the customer. The contract consideration in the Company’s variable price contracts are typically allocated to specific performance obligations in the contract according to the price stated in the contract. Amounts allocated in the Company’s fixed price contracts are based on the standalone selling price of those products in the context of long-term, fixed price contracts, which generally approximates the contract price. Payment is generally received one or two months after the sale has occurred. Gain or loss on derivative instruments is outside the scope of ASC 606 and is not considered revenue from contracts with customers subject to ASC 606. The Company may use financial or physical contracts accounted for as derivatives as economic hedges to manage price risk associated with normal sales, or in limited cases may use them for contracts the Company intends to physically settle but do not meet all of the criteria to be treated as normal sales. Taxes assessed by a governmental authority that are both imposed on and concurrent with a specific revenue-producing transaction, and that are collected by the Company from a customer, are excluded from revenue. Producer Gas Imbalances. The Company applies the sales method of accounting for natural gas revenue. Under this method, revenues are recognized based on the actual volume of natural gas sold to purchasers. Natural gas production operations may include joint owners who take more or less than the production volumes entitled to them on certain properties. Production volume is monitored to minimize these natural gas imbalances. Under this method, a natural gas imbalance liability is recorded if the Company's excess takes of natural gas exceed its estimated remaining proved developed reserves for these properties at the actual price realized upon the gas sale. A receivable is recognized only to the extent an imbalance cannot be recouped from the reserves in the underlying properties. The Company’s aggregate imbalance positions at March 31, 2018 and December 31, 2017 were not material. Brokered Natural Gas. Revenues and expenses related to brokered natural gas are reported gross as part of operating revenues and operating expenses in accordance with applicable accounting standards. The Company buys and sells natural gas utilizing separate purchase and sale transactions, typically with separate counterparties, whereby the Company and/or the counterparty obtains control of the natural gas purchased or sold. Disaggregation of Revenue. The following table presents revenues disaggregated by product: Three Months Ended March 31, (In thousands) 2018 2017 (1) OPERATING REVENUES Natural gas $ 412,108 $ 433,442 Crude oil and condensate 48,722 42,990 Brokered natural gas 4,950 4,695 Other 1,870 3,332 Total revenues from contracts with customers 467,650 484,459 Gain on derivative instruments 5,577 33,384 Total operating revenues $ 473,227 $ 517,843 _______________________________________________________________________________ (1) As noted above, prior period amounts have not been adjusted under the modified retrospective method. All of the Company’s revenues from contracts with customers represent products transferred at a point in time as control is transferred to the customer and are generated in the United States. Transaction Price Allocated to Remaining Performance Obligations. A significant number of the Company’s product sales are short-term in nature with a contract term of one year or less. For those contracts, the Company has utilized the practical expedient exempting the Company from disclosure of the transaction price allocated to remaining performance obligations if the performance obligation is part of a contract that has an original expected duration of one year or less. As of March 31, 2018 , the Company has $15.3 million of unsatisfied performance obligations related to natural gas sales that have a fixed pricing component and a contract term greater than one year. The Company expects to recognize these obligations over the next five years . Contract Balances. Receivables from contracts with customers are recorded when the right to consideration becomes unconditional, generally when control of the product has been transferred to the customer. Receivables from contracts with customers were $161.1 million and $215.5 million as of March 31, 2018 and December 31, 2017 , respectively, and are reported in accounts receivable, net on the Condensed Consolidated Balance Sheet. The Company currently has no assets or liabilities related to its revenue contracts, including no upfront or rights to deficiency payments. Practical Expedients. The Company has made use of certain practical expedients in adopting the new revenue standard, including the value of unsatisfied performance obligations are not disclosed for (i) contracts with an original expected length of one year or less, (ii) contracts for which the Company recognizes revenue at the amount to which the Company has the right to invoice, (iii) variable consideration which is allocated entirely to a wholly unsatisfied performance obligation and meets the variable allocation criteria in the standard and (iv) only contracts that are not completed at transition. The Company has not adjusted the promised amount of consideration for the effects of a significant financing component if the Company expects, at contract inception, that the period between when the Company transfers a promised good or service to the customer and when the customer pays for that good or service will be one year or less.

Financial Statement Presentat20

Financial Statement Presentation (Tables)	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The following table presents revenues disaggregated by product: Three Months Ended March 31, (In thousands) 2018 2017 (1) OPERATING REVENUES Natural gas $ 412,108 $ 433,442 Crude oil and condensate 48,722 42,990 Brokered natural gas 4,950 4,695 Other 1,870 3,332 Total revenues from contracts with customers 467,650 484,459 Gain on derivative instruments 5,577 33,384 Total operating revenues $ 473,227 $ 517,843 _______________________________________________________________________________ (1) As noted above, prior period amounts have not been adjusted under the modified retrospective method.

Properties and Equipment, Net (

Properties and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2018
Property, Plant and Equipment [Abstract]
Schedule of properties and equipment, net	Properties and equipment, net are comprised of the following: (In thousands) March 31, December 31, Proved oil and gas properties $ 5,082,995 $ 4,932,512 Unproved oil and gas properties 194,003 190,474 Gathering and pipeline systems 1,569 1,569 Land, building and other equipment 81,957 82,670 5,360,524 5,207,225 Accumulated depreciation, depletion and amortization (2,214,272 ) (2,135,021 ) $ 3,146,252 $ 3,072,204

Equity Method Investments (Tabl

Equity Method Investments (Tables)	3 Months Ended
	Mar. 31, 2018
Equity Method Investments and Joint Ventures [Abstract]
Summary of Information Related to the Company's Equity Method Investments	Activity related to these equity method investments is as follows: Constitution Meade Total Three Months Ended March 31, (In thousands) 2018 2017 2018 2017 2018 2017 Balance at beginning of period $ 732 $ 96,850 $ 85,345 $ 32,674 $ 86,077 $ 129,524 Contributions 250 1,125 35,168 6,617 35,418 7,742 Loss on equity method investments (982 ) (1,282 ) (12 ) (1 ) (994 ) (1,283 ) Balance at end of period $ — $ 96,693 $ 120,501 $ 39,290 $ 120,501 $ 135,983

Debt and Credit Agreements (Tab

Debt and Credit Agreements (Tables)	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Debt and credit agreement components	The Company’s debt and credit agreements consisted of the following: (In thousands) March 31, December 31, Total debt 6.51% weighted-average senior notes (1) $ 361,000 $ 361,000 9.78% senior notes (2) 67,000 67,000 5.58% weighted-average senior notes 175,000 175,000 3.65% weighted-average senior notes 925,000 925,000 Revolving credit facility — — Unamortized debt issuance costs (5,769 ) (6,109 ) $ 1,522,231 $ 1,521,891 _______________________________________________________________________________ (1) Includes $237.0 million of current portion of long-term debt at March 31, 2018 and December 31, 2017 , respectively. (2) Includes $67.0 million of current portion of long-term debt at March 31, 2018 and December 31, 2017 , respectively.

Derivative Instruments and He24

Derivative Instruments and Hedging Activities (Tables)	3 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Outstanding commodity derivatives	As of March 31, 2018 , the Company had the following outstanding financial commodity derivatives: Basis Swaps Swaps Type of Contract Volume Contract Period Weighted-Average Weighted-Average Financial contracts Natural gas (Leidy) 26.7 Bcf Apr. 2018 - Dec. 2018 $ (0.69 ) Natural gas (Transco) 18.7 Bcf Apr. 2018 - Dec. 2019 $ 0.42 Natural gas (NYMEX) 69.5 Bcf Apr. 2018 - Dec. 2018 $ 2.93 Natural gas (NYMEX) 10.4 Bcf Apr. 2018 - Oct. 2018 $ 3.10 As of March 31, 2018 , the Company had the following outstanding physical commodity derivatives: Type of Contract Volume Contract Period Weighted-Average Fixed Price Physical contracts Natural gas purchase 10.4 Bcf Apr. 2018 - Oct. 2018 $ 3.67
Effect of derivative instruments on the condensed consolidated balance sheet	Effect of Derivative Instruments on the Condensed Consolidated Balance Sheet Derivative Assets Derivative Liabilities (In thousands) Balance Sheet Location March 31, December 31, March 31, December 31, Commodity contracts Derivative instruments (current) $ 5,551 $ — $ 8,002 $ 30,637 Commodity contracts Derivative instruments (non-current) 5,762 2,239 — — $ 11,313 $ 2,239 $ 8,002 $ 30,637
Schedule of offsetting of derivative liabilities in the condensed consolidated balance sheet	Offsetting of Derivative Assets and Liabilities in the Condensed Consolidated Balance Sheet (In thousands) March 31, December 31, Derivative assets Gross amounts of recognized assets $ 11,950 $ 2,239 Gross amounts offset in the statement of financial position (637 ) — Net amounts of assets presented in the statement of financial position 11,313 2,239 Gross amounts of financial instruments not offset in the statement of financial position 4,728 — Net amount $ 16,041 $ 2,239 Derivative liabilities Gross amounts of recognized liabilities $ 8,639 $ 30,637 Gross amounts offset in the statement of financial position (637 ) — Net amounts of liabilities presented in the statement of financial position 8,002 30,637 Gross amounts of financial instruments not offset in the statement of financial position 5,534 241 Net amount $ 13,536 $ 30,878
Schedule of offsetting of derivative assets in the condensed consolidated balance sheet	Offsetting of Derivative Assets and Liabilities in the Condensed Consolidated Balance Sheet (In thousands) March 31, December 31, Derivative assets Gross amounts of recognized assets $ 11,950 $ 2,239 Gross amounts offset in the statement of financial position (637 ) — Net amounts of assets presented in the statement of financial position 11,313 2,239 Gross amounts of financial instruments not offset in the statement of financial position 4,728 — Net amount $ 16,041 $ 2,239 Derivative liabilities Gross amounts of recognized liabilities $ 8,639 $ 30,637 Gross amounts offset in the statement of financial position (637 ) — Net amounts of liabilities presented in the statement of financial position 8,002 30,637 Gross amounts of financial instruments not offset in the statement of financial position 5,534 241 Net amount $ 13,536 $ 30,878
Effect of derivatives on the condensed consolidated statement of operations	Effect of Derivative Instruments on the Condensed Consolidated Statement of Operations Three Months Ended (In thousands) 2018 2017 Cash received (paid) on settlement of derivative instruments Gain (loss) on derivative instruments $ (26,131 ) $ (1,524 ) Non-cash gain (loss) on derivative instruments Gain (loss) on derivative instruments 31,708 34,908 $ 5,577 $ 33,384

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Financial assets and liabilities measured at fair value on a recurring basis	The following fair value hierarchy table presents information about the Company’s financial assets and liabilities measured at fair value on a recurring basis: (In thousands) Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Balance at Assets Deferred compensation plan $ 15,717 $ — $ — $ 15,717 Derivative instruments — 3,326 7,987 11,313 Total assets $ 15,717 $ 3,326 $ 7,987 $ 27,030 Liabilities Deferred compensation plan $ 27,605 $ — $ — $ 27,605 Derivative instruments — — 8,002 8,002 Total liabilities $ 27,605 $ — $ 8,002 $ 35,607 (In thousands) Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Balance at Assets Deferred compensation plan $ 14,966 $ — $ — $ 14,966 Derivative instruments — — 2,239 2,239 Total assets $ 14,966 $ — $ 2,239 $ 17,205 Liabilities Deferred compensation plan $ 29,145 $ — $ — $ 29,145 Derivative instruments — — 30,637 30,637 Total liabilities $ 29,145 $ — $ 30,637 $ 59,782
Reconciliation of changes in the fair value of financial assets and liabilities classified as level 3	The following table sets forth a reconciliation of changes in the fair value of financial assets and liabilities classified as Level 3 in the fair value hierarchy: Three Months Ended (In thousands) 2018 2017 Balance at beginning of period $ (28,398 ) $ (15,868 ) Total gain (loss) included in earnings 6,628 21,918 Settlement (gain) loss 21,755 (981 ) Transfers in and/or out of level 3 — — Balance at end of period $ (15 ) $ 5,069 Change in unrealized gains (losses) relating to assets and liabilities still held at the end of the period $ 2,217 $ 20,937
Carrying amounts and fair values of debt	The carrying amount and fair value of debt is as follows: March 31, 2018 December 31, 2017 (In thousands) Carrying Amount Estimated Fair Value Carrying Amount Estimated Fair Value Long-term debt $ 1,522,231 $ 1,499,909 $ 1,521,891 $ 1,527,624 Current maturities (304,000 ) (308,846 ) (304,000 ) (312,055 ) Long-term debt, excluding current maturities $ 1,218,231 $ 1,191,063 $ 1,217,891 $ 1,215,569

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	3 Months Ended
	Mar. 31, 2018
Asset Retirement Obligation Disclosure [Abstract]
Activity Related to Asset Retirement Obligations	Activity related to the Company’s asset retirement obligations is as follows: (In thousands) Three Months Ended Balance at beginning of period (1) $ 48,553 Liabilities incurred 1,546 Liabilities settled (413 ) Liabilities divested (3,782 ) Accretion expense 603 Balance at end of period (2) $ 46,507 _______________________________________________________________________________ (1) Includes $5.0 million of current asset retirement obligations included in accrued liabilities at December 31, 2017 . (2) Includes $1.0 million of current asset retirement obligations included in accrued liabilities at March 31, 2018 .

Stock-based Compensation (Table

Stock-based Compensation (Tables)	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions	The following assumptions were used to determine the grant date fair value of the equity component (February 21, 2018 ) and the period-end fair value of the liability component of the TSR Performance Share Awards: Grant Date March 31, 2018 Fair value per performance share award $ 19.92 $8.44-$17.09 Assumptions: Stock price volatility 37.3 % 26.0% - 38.1% Risk free rate of return 2.40 % 2.00% - 2.35%

Earnings per Common Share (Tabl

Earnings per Common Share (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share [Abstract]
Calculation of basic and diluted weighted-average shares outstanding	The following is a calculation of basic and diluted weighted-average shares outstanding: Three Months Ended (In thousands) 2018 2017 Weighted-average shares - basic 459,715 465,348 Dilution effect of stock appreciation rights and stock awards at end of period 1,834 1,540 Weighted-average shares - diluted 461,549 466,888
Calculation of weighted-average shares excluded from diluted EPS due to the anti-dilutive effect	The following is a calculation of weighted-average shares excluded from diluted EPS due to the anti-dilutive effect: Three Months Ended (In thousands) 2018 2017 Weighted-average stock appreciation rights and stock awards excluded from diluted EPS due to the anti-dilutive effect calculated using the treasury stock method 608 477

Additional Balance Sheet Info29

Additional Balance Sheet Information (Tables)	3 Months Ended
	Mar. 31, 2018
Balance Sheet Related Disclosures [Abstract]
Additional Balance Sheet Information	Certain balance sheet amounts are comprised of the following: (In thousands) March 31, December 31, Accounts receivable, net Trade accounts $ 161,085 $ 215,511 Joint interest accounts 673 467 Other accounts 9,528 1,312 171,286 217,290 Allowance for doubtful accounts (1,286 ) (1,286 ) $ 170,000 $ 216,004 Other assets Deferred compensation plan $ 15,717 $ 14,966 Debt issuance costs 7,136 7,990 Other accounts 108 56 $ 22,961 $ 23,012 Accounts payable Trade accounts $ 19,858 $ 7,815 Natural gas purchases 3,468 4,299 Royalty and other owners 27,614 39,207 Accrued transportation 46,704 51,433 Accrued capital costs 42,162 31,130 Taxes other than income 20,087 16,801 Deposits received for asset sales 5,000 81,500 Other accounts 9,769 5,860 $ 174,662 $ 238,045 Accrued liabilities Employee benefits $ 8,431 $ 20,645 Taxes other than income 1,525 550 Income taxes payable 109 — Asset retirement obligations 1,000 4,952 Other accounts 505 1,294 $ 11,570 $ 27,441 Other liabilities Deferred compensation plan $ 27,605 $ 29,145 Other accounts 7,182 10,578 $ 34,787 $ 39,723

Financial Statement Presentat30

Financial Statement Presentation - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Unsatisfied performance obligations	$ 15.3
Unsatisfied performance obligations, expected period of satisfaction	5 years
Contracts with customers	$ 161.1	$ 215.5

Financial Statement Presentat31

Financial Statement Presentation - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	$ 467,650	$ 484,459
Gain on derivative instruments	5,577	33,384
TOTAL OPERATING REVENUES	473,227	517,843
Natural gas
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	412,108	433,442
Crude oil and condensate
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	48,722	42,990
Brokered natural gas
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	4,950	4,695
Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	$ 1,870	$ 3,332

Properties and Equipment, Net -

Properties and Equipment, Net - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Proved oil and gas properties	$ 5,082,995	$ 4,932,512
Unproved oil and gas properties	194,003	190,474
Gathering and pipeline systems	1,569	1,569
Land, building and other equipment	81,957	82,670
Properties and equipment, gross, total	5,360,524	5,207,225
Accumulated depreciation, depletion and amortization	(2,214,272)	(2,135,021)
Properties and equipment, net	$ 3,146,252	$ 3,072,204

Properties and Equipment, Net33

Properties and Equipment, Net - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Feb. 29, 2016	Mar. 31, 2018	Mar. 31, 2017
Property, Plant and Equipment [Line Items]
Proceeds from sale of assets		$ 646,545	$ 374
Gain (loss) on sale of assets		(41,049)	$ (223)
East Texas | Oil and Gas Properties, Proved and Unproved
Property, Plant and Equipment [Line Items]
Proceeds from sale of assets	$ 765,000
Impairment of oil and gas properties and other assets	$ 414,300
West Virginia, Virginia, and Ohio | Oil and Gas Properties, Proved and Unproved
Property, Plant and Equipment [Line Items]
Gain (loss) on sale of assets		$ (44,800)

Equity Method Investments - Act

Equity Method Investments - Activity Related to Equity Method Investments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Equity Method Investments
Balance at beginning of period	$ 86,077	$ 129,524
Contributions	35,418	7,742
Loss on equity method investments	(994)	(1,283)
Balance at end of period	$ 120,501	135,983
Constitution
Schedule of Equity Method Investments [Line Items]
Ownership percentage	25.00%
Equity Method Investments
Balance at beginning of period	$ 732	96,850
Contributions	250	1,125
Loss on equity method investments	(982)	(1,282)
Balance at end of period	0	96,693
Basis difference in investment	$ 95,900
Meade
Schedule of Equity Method Investments [Line Items]
Ownership percentage	20.00%
Equity Method Investments
Balance at beginning of period	$ 85,345	32,674
Contributions	35,168	6,617
Loss on equity method investments	(12)	(1)
Balance at end of period	120,501	$ 39,290
Investment Commitment
Equity Method Investments
Expected future contributions	$ 60,000

Debt and Credit Agreements - Sc

Debt and Credit Agreements - Schedule of Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Unamortized debt issuance costs	$ (5,769)	$ (6,109)
Long-term debt, net	1,522,231	1,521,891
Current maturities	304,000	304,000
6.51% weighted-average senior notes
Debt Instrument [Line Items]
Total debt	$ 361,000	$ 361,000
Weighted average interest rate	6.51%	6.51%
Current maturities	$ 237,000
9.78% senior notes
Debt Instrument [Line Items]
Total debt	$ 67,000	$ 67,000
Long-term debt, interest rate, stated percentage	9.78%	9.78%
Current maturities	$ 67,000
5.58% weighted-average senior notes
Debt Instrument [Line Items]
Total debt	$ 175,000	$ 175,000
Weighted average interest rate	5.58%	5.58%
3.65% weighted-average senior notes
Debt Instrument [Line Items]
Total debt	$ 925,000	$ 925,000
Weighted average interest rate	3.65%	3.65%
Revolving credit facility
Debt Instrument [Line Items]
Total debt	$ 0	$ 0

Debt and Credit Agreements - Na

Debt and Credit Agreements - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Apr. 11, 2017
Debt Instrument [Line Items]
Change in interest rate during period	0.00%
Revolving credit facility
Debt Instrument [Line Items]
Borrowing base		$ 3,200,000,000
Remaining borrowing capacity	$ 1,700,000,000	$ 1,700,000,000
Line of credit	$ 0

Derivative Instruments and He37

Derivative Instruments and Hedging Activities - Outstanding Commodity Derivatives (Details) Bcf in Millions	3 Months Ended
	Mar. 31, 2018$ / McfBcf
Natural gas (Leidy)
Derivative [Line Items]
Volume (in Bcf for gas and mmbbls for oil) | Bcf	26.7
Swaps Weighted Average (in usd per Mcf or usd per bbl) | $ / Mcf	(0.69)
Natural gas (Transco)
Derivative [Line Items]
Volume (in Bcf for gas and mmbbls for oil) | Bcf	18.7
Swaps Weighted Average (in usd per Mcf or usd per bbl) | $ / Mcf	0.42
Natural gas (NYMEX)
Derivative [Line Items]
Volume (in Bcf for gas and mmbbls for oil) | Bcf	69.5
Swaps Weighted Average (in usd per Mcf or usd per bbl) | $ / Mcf	2.93
Natural gas (NYMEX)
Derivative [Line Items]
Volume (in Bcf for gas and mmbbls for oil) | Bcf	10.4
Swaps Weighted Average (in usd per Mcf or usd per bbl) | $ / Mcf	3.10
Natural gas purchase
Derivative [Line Items]
Volume (in Bcf for gas and mmbbls for oil) | Bcf	0
Swaps Weighted Average (in usd per Mcf or usd per bbl) | $ / Mcf	3.67

Derivative Instruments and He38

Derivative Instruments and Hedging Activities - Effect of Derivative Instruments on the Condensed Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Effect of derivative instruments on the Consolidated Balance Sheet
Derivative Assets	$ 11,313	$ 2,239
Derivatives Not Designated as Hedges | Commodity contracts
Effect of derivative instruments on the Consolidated Balance Sheet
Derivative Assets	11,313	2,239
Derivative Liabilities	8,002	30,637
Derivative instruments (current) | Derivatives Not Designated as Hedges | Commodity contracts
Effect of derivative instruments on the Consolidated Balance Sheet
Derivative Assets	5,551	0
Derivative Liabilities	8,002	30,637
Derivative instruments (non-current) | Derivatives Not Designated as Hedges | Commodity contracts
Effect of derivative instruments on the Consolidated Balance Sheet
Derivative Assets	5,762	2,239
Derivative Liabilities	$ 0	$ 0

Derivative Instruments and He39

Derivative Instruments and Hedging Activities - Offsetting of Derivative Assets and Liabilities in the Condensed Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Derivative assets
Gross amounts of recognized assets	$ 11,950	$ 2,239
Gross amounts offset in the statement of financial position	(637)	0
Net amounts of assets presented in the statement of financial position	11,313	2,239
Gross amounts of financial instruments not offset in the statement of financial position	4,728	0
Net amount	16,041	2,239
Derivative liabilities
Gross amounts of recognized liabilities	8,639	30,637
Gross amounts offset in the statement of financial position	(637)	0
Net amounts of liabilities presented in the statement of financial position	8,002	30,637
Gross amounts of financial instruments not offset in the statement of financial position	5,534	241
Net amount	$ 13,536	$ 30,878

Derivative Instruments and He40

Derivative Instruments and Hedging Activities - Effect of Derivative Instruments on the Condensed Consolidated Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Cash received (paid) on settlement of derivative instruments, gain (loss) on derivative instruments	$ (26,131)	$ (1,524)
Non-cash gain (loss) on derivative instruments, gain (loss) on derivative instruments	31,708	34,908
Gain (loss) on derivative instruments	$ 5,577	$ 33,384

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities, Recurring (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Assets
Deferred compensation plan	$ 15,717	$ 14,966
Derivative instruments	11,950	2,239
Liabilities
Deferred compensation plan	27,605	29,145
Recurring basis
Assets
Deferred compensation plan	15,717	14,966
Derivative instruments	11,313	2,239
Total assets	27,030	17,205
Liabilities
Deferred compensation plan	27,605	29,145
Derivative instruments	8,002	30,637
Total liabilities	35,607	59,782
Quoted Prices in Active Markets for Identical Assets (Level 1) | Recurring basis
Assets
Deferred compensation plan	15,717	14,966
Derivative instruments	0	0
Total assets	15,717	14,966
Liabilities
Deferred compensation plan	27,605	29,145
Derivative instruments	0	0
Total liabilities	27,605	29,145
Significant Other Observable Inputs (Level 2) | Recurring basis
Assets
Deferred compensation plan	0	0
Derivative instruments	3,326	0
Total assets	3,326	0
Liabilities
Deferred compensation plan	0	0
Derivative instruments	0	0
Total liabilities	0	0
Significant Unobservable Inputs (Level 3) | Recurring basis
Assets
Deferred compensation plan	0	0
Derivative instruments	7,987	2,239
Total assets	7,987	2,239
Liabilities
Deferred compensation plan	0	0
Derivative instruments	8,002	30,637
Total liabilities	$ 8,002	$ 30,637

Fair Value Measurements - Recon

Fair Value Measurements - Reconciliation of Changes in Fair Value of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Reconciliation of changes in the fair value of financial assets and liabilities classified as Level 3 in the fair value hierarchy
Balance at beginning of period	$ (28,398)	$ (15,868)
Total gain (loss) included in earnings	6,628	21,918
Settlement (gain) loss	21,755	(981)
Transfers in and/or out of level 3	0	0
Balance at end of period	(15)	5,069
Change in unrealized gains (losses) relating to assets and liabilities still held at the end of the period	$ 2,217	$ 20,937

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details)	3 Months Ended
	Mar. 31, 2018USD ($)impaired_asset_and_liability	Mar. 31, 2017impaired_asset_and_liability	Dec. 31, 2017USD ($)
Fair Value Disclosures [Abstract]
Fair value assets, level 1 to level 2	$ 0		$ 0
Fair value liabilities, level 1 to level 2	0		0
Fair value assets, level 2 to level 1	0		0
Fair value liabilities, level 2 to level 1	$ 0		$ 0
Number of non-financial assets and liabilities impaired | impaired_asset_and_liability	0	0

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value of Other Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair value disclosures
Long-term debt	$ 1,522,231	$ 1,521,891
Current maturities	(304,000)	(304,000)
Long-term debt, excluding current maturities	1,218,231	1,217,891
Carrying Amount
Fair value disclosures
Long-term debt	1,522,231	1,521,891
Current maturities	(304,000)	(304,000)
Long-term debt, excluding current maturities	1,218,231	1,217,891
Estimated Fair Value
Fair value disclosures
Long-term debt	1,499,909	1,527,624
Current maturities	(308,846)	(312,055)
Long-term debt, excluding current maturities	$ 1,191,063	$ 1,215,569

Asset Retirement Obligations -

Asset Retirement Obligations - Schedule of ARO (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018USD ($)
Asset Retirement Obligation
Balance at beginning of period(1)	$ 48,553
Liabilities incurred	1,546
Liabilities settled	(413)
Liabilities divested	(3,782)
Accretion expense	603
Balance at end of period(2)	$ 46,507

Asset Retirement Obligations 46

Asset Retirement Obligations - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Asset retirement obligations	$ 1,000	$ 4,952
Accrued Liabilities
Property, Plant and Equipment [Line Items]
Asset retirement obligations	$ 1,000	$ 5,000

Capital Stock - Narrative (Deta

Capital Stock - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended
	Apr. 30, 2018	Feb. 28, 2018	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Equity [Abstract]
Incremental shares authorized		25,000,000
Treasury stock			23,263,707		14,935,926
Shares authorized for repurchase		30,100,000
Remaining shares available for repurchase (in shares)			21,700,000
Subsequent Event [Line Items]
Shares repurchased			8,300,000
Treasury stock repurchases (in usd)			$ 207,134	$ 0
Subsequent Event
Subsequent Event [Line Items]
Shares repurchased	1,600,000
Treasury stock repurchases (in usd)	$ 38,500

Stock-based Compensation - Narr

Stock-based Compensation - Narrative (Details) - USD ($)	Feb. 17, 2016	Mar. 31, 2018	Mar. 31, 2017
Stock-based Compensation arrangements
Stock based compensation expense		$ 5,400,000	$ 8,300,000
Restricted Stock Units
Stock-based Compensation arrangements
Granted (in shares)		71,400
Granted (in dollars per share)		$ 23.42
Performance Share Awards | Minimum
Stock-based Compensation arrangements
Annual forfeiture rate assumption (as a percent)		0.00%
Performance Share Awards | Maximum
Stock-based Compensation arrangements
Annual forfeiture rate assumption (as a percent)		5.00%
Performance Share Awards Based on Internal Performance Metrics
Stock-based Compensation arrangements
Right to receive additional shares, maximum (as a percent)		100.00%
Employee Performance Share Awards
Stock-based Compensation arrangements
Granted (in shares)		531,670
Granted (in dollars per share)		$ 23.25
Number of years over which performance criteria is to be met		3 years
Hybrid Performance Share Awards
Stock-based Compensation arrangements
Granted (in shares)		321,720
Granted (in dollars per share)		$ 23.25
Minimum operating cash flow for the year preceding the performance period		$ 100,000,000
Hybrid Performance Share Awards | Hybrid performance share awards, percentage vesting on the first anniversary
Stock-based Compensation arrangements
Award vesting rights (as a percent)		25.00%
Hybrid Performance Share Awards | Hybrid performance share awards, percentage vesting on the second anniversary
Stock-based Compensation arrangements
Award vesting rights (as a percent)		25.00%
Hybrid Performance Share Awards | Hybrid performance share awards, percentage vesting on the third anniversary
Stock-based Compensation arrangements
Award vesting rights (as a percent)		50.00%
Performance Shares Based on Market Conditions
Stock-based Compensation arrangements
Right to receive shares (as a percent)		100.00%
Right to receive an additional award in cash (as a percent)		100.00%
TSR Performance Share Awards
Stock-based Compensation arrangements
Granted (in shares)		482,581
Granted (in dollars per share)	$ 19.92
Performance period		3 years
TSR Performance Share Awards | Minimum
Stock-based Compensation arrangements
Granted (in dollars per share)		$ 8.44
TSR Performance Share Awards | Maximum
Stock-based Compensation arrangements
Granted (in dollars per share)		$ 17.09

Stock-based Compensation - Assu

Stock-based Compensation - Assumptions for TSR Shares (Details) - TSR Performance Share Awards - $ / shares	Feb. 17, 2016	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in dollars per share)	$ 19.92
Stock price volatility	37.30%
Risk free rate of return	2.40%
Minimum expected volatility		26.00%
Maximum expected volatility		38.10%
Minimum risk free interest rate		2.00%
Maximum risk free interest rate		2.35%
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in dollars per share)		$ 8.44
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in dollars per share)		$ 17.09

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Decrease in income taxes	$ (23.6)
Effective tax rate	25.30%	37.40%

Earnings per Common Share - Sch

Earnings per Common Share - Schedule of EPS (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share [Abstract]
Weighted-average shares - basic	459,715	465,348
Dilution effect of stock appreciation rights and stock awards at end of period	1,834	1,540
Weighted-average shares - diluted	461,549	466,888

Earnings per Common Share - Cal

Earnings per Common Share - Calculation of Weighted-Average Shares Excluded from Diluted EPS (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Stock appreciation rights and stock awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Weighted-average stock appreciation rights and stock awards excluded from diluted EPS due to the anti-dilutive effect calculated using the treasury stock method	608	477

Additional Balance Sheet Info53

Additional Balance Sheet Information - Schedule of Additional Balance Sheet Information (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Accounts receivable, net
Trade accounts	$ 161,085	$ 215,511
Joint interest accounts	673	467
Other accounts	9,528	1,312
Accounts receivable, net	171,286	217,290
Allowance for doubtful accounts	(1,286)	(1,286)
Accounts receivable, net	170,000	216,004
Other assets
Deferred compensation plan	15,717	14,966
Debt issuance costs	7,136	7,990
Other accounts	108	56
Other assets	22,961	23,012
Accounts payable
Trade accounts	19,858	7,815
Natural gas purchases	3,468	4,299
Royalty and other owners	27,614	39,207
Accrued transportation	46,704	51,433
Accrued capital costs	42,162	31,130
Taxes other than income	20,087	16,801
Deposits received for asset sales	5,000	81,500
Other accounts	9,769	5,860
Accounts payable	174,662	238,045
Accrued liabilities
Employee benefits	8,431	20,645
Taxes other than income	1,525	550
Income taxes payable	109	0
Asset retirement obligations	1,000	4,952
Other accounts	505	1,294
Accrued liabilities	11,570	27,441
Other liabilities
Deferred compensation plan	27,605	29,145
Other accounts	7,182	10,578
Other liabilities	$ 34,787	$ 39,723