Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net income	$ 213,534	$ 22,812
Depreciation and amortization	377,722	398,013
Other operating activities and non-cash items	20,368	51,533
Changes in assets and liabilities	(177,576)	(189,026)
Net cash provided by operating activities	434,048	283,332
Cash flows from investing activities:
Payments for property, plant and equipment	(275,531)	(328,497)
Proceeds from sale of property, plant and equipment	2,710	8,495
Proceeds from insurance recovery for property, plant and equipment	0	1,538
Payments for short-term investments	(475,696)	(5,935)
Proceeds from sale of short-term investments	37,633	0
Proceeds from maturities of short-term investments	86,216	6,469
Other investing activities	13,331	(887)
Net cash used in investing activities	(611,337)	(318,817)
Cash flows from financing activities:
Proceeds from revolving credit facilities	312,000	172,700
Repayments of revolving credit facilities	(332,000)	(92,700)
Proceeds from short-term debt	86,769	51,434
Payments of short-term debt	(76,004)	(42,067)
Proceeds from issuance of long-term debt	225,985	714,375
Payments of long-term debt	(370,426)	(847,155)
Payments of finance lease obligations	(7,193)	(4,358)
Other financing activities	7,707	(1,963)
Net cash used in financing activities	(153,162)	(49,734)
Effect of exchange rate fluctuations on cash, cash equivalents and restricted cash	2,696	1,385
Net decrease in cash, cash equivalents and restricted cash	(327,755)	(83,834)
Cash, cash equivalents and restricted cash, beginning of period	898,532	688,051
Cash, cash equivalents and restricted cash, end of period	570,777	604,217
Non-cash investing and financing activities:
Property, plant and equipment included in capital expenditures payable	$ 328,354	$ 157,959