CONSOLIDATED STATEMENT OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 681,070	$ 557,043	$ 100,393
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation, depletion and amortization	405,733	417,479	568,817
Impairment of oil and gas properties	0	0	482,811
Deferred income tax expense (benefit)	244,418	229,603	(321,113)
Loss on sale of assets	1,462	16,327	11,565
Exploratory dry hole cost	2,236	97,741	3,820
Gain on derivative instruments	(80,808)	(44,432)	(16,926)
Net cash received (paid) in settlement of derivative instruments	138,450	(41,631)	8,056
(Earnings) loss on equity method investments	(80,496)	(1,137)	100,486
Distribution of earnings from equity method investments	15,725	1,296	0
Amortization of debt issuance costs	3,966	4,631	4,774
Stock-based compensation and other	29,009	31,443	33,419
Changes in assets and liabilities:
Accounts receivable, net	153,379	(146,921)	(25,036)
Income taxes	(13,514)	(59,616)	(46,368)
Inventories	(2,856)	(3,927)	1,334
Other current assets	180	934	(104)
Accounts payable and accrued liabilities	(30,176)	30,468	(2,552)
Interest payable	(166)	(7,477)	(75)
Other assets and liabilities	(21,821)	23,079	(5,141)
Net cash provided by operating activities	1,445,791	1,104,903	898,160
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(788,368)	(894,470)	(764,558)
Proceeds from sale of assets	2,600	678,350	115,444
Investment in equity method investments	(9,338)	(77,263)	(57,039)
Distribution of investment from equity method investments	1,728	0	0
Proceeds from sale of equity method investments	249,463	0	0
Net cash used in investing activities	(543,915)	(293,383)	(706,153)
CASH FLOWS FROM FINANCING ACTIVITIES
Borrowings from debt	95,000	158,000	0
Repayments of debt	(102,000)	(455,000)	0
Treasury stock repurchases	(519,863)	(872,761)	(123,741)
Dividends paid	(145,515)	(111,369)	(78,838)
Tax withholding on vesting of stock awards	(10,590)	(8,150)	(7,973)
Capitalized debt issuance costs	(7,412)	0	0
Other	0	0	50
Net cash used in financing activities	(690,380)	(1,289,280)	(210,502)
Net increase (decrease) in cash, cash equivalents and restricted cash	211,496	(477,760)	(18,495)
Cash, cash equivalents and restricted cash, beginning of period	2,287	480,047	498,542
Cash, cash equivalents and restricted cash, end of period	$ 213,783	$ 2,287	$ 480,047