Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net loss	$ (255,721)	$ (858,115)	$ (205,921)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation, depletion, amortization and accretion	271,410	400,848	438,716
Deferred income taxes	3,247	(61,058)	(182,553)
Reduction in value of assets	93,763	739,725	14,155
Right-of-use assets amortization	20,613
Stock based compensation expense	19,814	31,451	36,503
Other reconciling items, net	(16,023)	(9,545)	2,505
Changes in operating assets and liabilities:
Accounts receivable	104,538	(50,116)	(93,309)
Prepaid expenses	(4,956)	(2,373)	(5,441)
Inventory and other current assets	(6,137)	(7,559)	(2,455)
Accounts payable	(12,278)	8,912	23,648
Accrued expenses	(37,482)	(21,113)	(8,458)
Income taxes	(1,258)	2,320	99,089
Other, net	(33,102)	(8,320)	(20,053)
Net cash provided by operating activities	146,428	165,057	96,426
Cash flows from investing activities:
Payments for capital expenditures	(140,465)	(221,370)	(164,933)
Proceeds from sales of assets	110,008	33,299	28,269
Net cash used in investing activities	(30,457)	(188,071)	(136,664)
Cash flows from financing activities:
Proceeds from issuance of long-term debt			500,000
Principal payments on long-term debt			(500,000)
Payment of debt issuance costs			(11,967)
Purchases of treasury stock	(4,290)
Tax withholdings for vested restricted stock units	(1,677)	(5,199)	(8,326)
Other	675	2,613	3,268
Net cash used in financing activities	(5,292)	(2,586)	(17,025)
Effect of exchange rate changes on cash	961	(3,135)	3,654
Net change in cash, cash equivalents, and restricted cash	111,640	(28,735)	(53,609)
Cash, cash equivalents, and restricted cash at beginning of period	163,748	192,483	246,092
Cash, cash equivalents, and restricted cash at end of period	275,388	163,748	192,483
Cash Payments:
Interest paid	99,585	101,056	88,125
Income taxes paid (net of income tax refunds received)	5,354	3,137	(117,376)
Non-cash investing activity:
Capital expenditures included in accounts payable and accrued expenses	$ 10,567	$ 26,259	$ 11,522