Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net income (loss)	$ 10,195	$ (13,968)
Depreciation and amortization	142,509	141,816
Other operating activities and non-cash items	(4,734)	(9,653)
Changes in assets and liabilities	(339)	(15,518)
Net cash provided by operating activities	147,631	102,677
Cash flows from investing activities:
Payments for property, plant and equipment	(230,603)	(88,285)
Proceeds from sale of property, plant and equipment	342	1,835
Other investing activities	656	(2,492)
Net cash used in investing activities	(229,605)	(88,942)
Cash flows from financing activities:
Proceeds from short-term debt	0	13,275
Payments of short-term debt	(17,352)	(14,073)
Proceeds from issuance of long-term debt	0	50,000
Payments of long-term debt	(6,220)	(3,295)
Payment of deferred consideration for purchase of facility	0	(3,890)
Payments of capital lease obligations	(808)	(913)
Other financing activities	455	(356)
Net cash provided by (used in) financing activities	(23,925)	40,748
Effect of exchange rate fluctuations on cash, cash equivalents and restricted cash	3,892	10,259
Net increase (decrease) in cash, cash equivalents and restricted cash	(102,007)	64,742
Cash, cash equivalents and restricted cash, beginning of period	602,851	555,495
Cash, cash equivalents and restricted cash, end of period	500,844	620,237
Non-cash investing and financing activities:
Property, plant and equipment included in capital expenditures payable	224,037	211,410
Equipment acquired through capital lease	$ 923	$ 0