Supplemental Guarantor Information (Condensed Consolidating Statements of Cash Flows) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net cash provided by (used in) operating activities	$ 116,504	$ 83,356
Cash flows from investing activities:
Payments for capital expenditures	(105,393)	(186,283)
Proceeds from sales of assets	90,696	29,595
Net cash used in investing activities	(14,697)	(156,688)
Cash flows from financing activities:
Other	(1,056)	(3,950)
Net cash provided by (used in) financing activities	(1,056)	(3,950)
Effect of exchange rate changes on cash	(1,857)	(1,834)
Net change in cash, cash equivalents, and restricted cash	98,894	(79,116)
Cash, cash equivalents, and restricted cash at beginning of period	163,748	192,483
Cash, cash equivalents, and restricted cash at end of period	262,642	113,367
Eliminations [Member]
Cash flows from operating activities:
Net cash provided by (used in) operating activities		(14,269)
Cash flows from financing activities:
Intercompany dividends		14,269
Net cash provided by (used in) financing activities		14,269
Parent [Member]
Cash flows from operating activities:
Net cash provided by (used in) operating activities	14,295	18,290
Cash flows from financing activities:
Changes in notes with affiliated companies, net	(13,270)	(14,775)
Other	(1,025)	(3,515)
Net cash provided by (used in) financing activities	(14,295)	(18,290)
Issuer [Member]
Cash flows from operating activities:
Net cash provided by (used in) operating activities	(272,879)	(118,313)
Cash flows from investing activities:
Payments for capital expenditures	(5,514)	(1,509)
Net cash used in investing activities	(5,514)	(1,509)
Cash flows from financing activities:
Changes in notes with affiliated companies, net	364,179	31,469
Other	(31)	(435)
Net cash provided by (used in) financing activities	364,148	31,034
Net change in cash, cash equivalents, and restricted cash	85,755	(88,788)
Cash, cash equivalents, and restricted cash at beginning of period	102,224	126,533
Cash, cash equivalents, and restricted cash at end of period	187,979	37,745
Guarantor Subsidiaries [Member]
Cash flows from operating activities:
Net cash provided by (used in) operating activities	350,633	174,198
Cash flows from investing activities:
Payments for capital expenditures	(94,757)	(175,524)
Proceeds from sales of assets	90,696	16,226
Net cash used in investing activities	(4,061)	(159,298)
Cash flows from financing activities:
Changes in notes with affiliated companies, net	(348,883)	(26,644)
Net cash provided by (used in) financing activities	(348,883)	(26,644)
Net change in cash, cash equivalents, and restricted cash	(2,311)	(11,744)
Cash, cash equivalents, and restricted cash at beginning of period	6,360	20,923
Cash, cash equivalents, and restricted cash at end of period	4,049	9,179
Non-Guarantor Subsidiaries [Member]
Cash flows from operating activities:
Net cash provided by (used in) operating activities	24,455	23,450
Cash flows from investing activities:
Payments for capital expenditures	(5,122)	(9,250)
Proceeds from sales of assets		13,369
Net cash used in investing activities	(5,122)	4,119
Cash flows from financing activities:
Intercompany dividends		(14,269)
Changes in notes with affiliated companies, net	(2,026)	9,950
Net cash provided by (used in) financing activities	(2,026)	(4,319)
Effect of exchange rate changes on cash	(1,857)	(1,834)
Net change in cash, cash equivalents, and restricted cash	15,450	21,416
Cash, cash equivalents, and restricted cash at beginning of period	55,164	45,027
Cash, cash equivalents, and restricted cash at end of period	$ 70,614	$ 66,443