CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 53,910	$ 262,763
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation, depletion and amortization	100,135	92,258
Deferred income tax expense	44,044	88,002
(Gain) loss on sale of assets	(71)	1,500
Gain on derivative instruments	(16,062)	(8,257)
Net cash received in settlement of derivative instruments	0	52,980
Loss (earnings) on equity method investments	59	(3,684)
Distribution of earnings from equity method investments	0	4,729
Amortization of debt issuance costs	750	1,089
Stock-based compensation and other	15,765	14,487
Changes in assets and liabilities:
Accounts receivable, net	73,327	141,671
Income taxes	(26,756)	6,786
Inventories	(4,317)	(7,201)
Other current assets	916	1,119
Accounts payable and accrued liabilities	(23,711)	(27,934)
Interest payable	(12,981)	(12,887)
Other assets and liabilities	(111)	(22,134)
Net cash provided by operating activities	204,897	585,287
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(148,702)	(195,650)
Proceeds from sale of assets	48	2,346
Investment in equity method investments	(35)	(1,828)
Proceeds from sale of equity method investments	(9,424)	0
Net cash used in investing activities	(158,113)	(195,132)
CASH FLOWS FROM FINANCING ACTIVITIES
Borrowings from debt	0	95,000
Repayments of debt	0	(102,000)
Treasury stock repurchases	0	(31,378)
Dividends paid	(39,817)	(29,605)
Tax withholdings on vesting of stock awards	(6,313)	(9,570)
Net cash used in financing activities	(46,130)	(77,553)
Net increase in cash, cash equivalents and restricted cash	654	312,602
Cash, cash equivalents and restricted cash, beginning of period	213,783	2,287
Cash, cash equivalents and restricted cash, end of period	$ 214,437	$ 314,889