CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income (loss)	$ (540,633)	$ (1,029,607)	$ (372,294)
Adjustments to net income (loss):
Depreciation and amortization	845,439	874,296	973,318
Deferred income tax expense (benefit)	9,096	(206,670)	(203,145)
Impairments and other charges	42,188	236,745	129,341
Deferred financing costs amortization	7,088	4,381	5,290
Discount amortization on long-term debt	20,495	2,074	1,969
Losses (gains) on debt buyback	16,005	(6,665)
Losses (gains) on long-lived assets, net	19,064	85,064	63,338
Losses (gains) on investments, net	972
Impairments on equity method holdings		216,242	180,591
Losses (gains) on merger and acquisitions			(49,382)
Share-based compensation	31,896	32,000	47,313
Foreign currency transaction losses (gains), net	1,604	5,669	9,881
Pension buyout		3,059
Equity in (earnings) losses of unconsolidated affiliates, net of dividends	(7)	221,914	84,275
Other	(5,542)	1,333	627
Changes in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable	(165,353)	250,400	529,151
Inventory	(17,444)	40,647	23,852
Other current assets	16,518	37,904	34,390
Other long-term assets	28,772	98	(27,461)
Trade accounts payable and accrued liabilities	79,204	(180,200)	(566,042)
Income taxes payable	14,811	(46,576)	(1,680)
Other long-term liabilities	(341,417)	(10,203)	(6,776)
Net cash (used for) provided by operating activities	62,756	531,905	856,556
Cash flows from investing activities:
Purchases of investments	(6,722)	(24)	(9)
Sales and maturities of investments	13,069	739	961
Cash paid for acquisition of businesses, net of cash acquired	9,040	(22,278)	(80,187)
Investment in unconsolidated affiliates			(445)
Capital expenditures	(574,467)	(395,455)	(867,106)
Proceeds from sales of assets and insurance claims	57,933	34,831	68,206
Proceeds from merger transaction			650,050
Other	(856)	64	1,081
Net cash (used for) provided by investing activities	(502,003)	(382,123)	(227,449)
Cash flows from financing activities:
Increase (decrease) in cash overdrafts	(188)	3	645
Proceeds from issuance of long-term debt	411,200	600,000
Debt issuance costs	(11,043)	(11,520)	(1,847)
Proceeds from revolving credit facilities	725,000	611,500	3,972
Reduction in revolving credit facilities	(215,000)	(611,500)	(450,000)
Proceeds from (payments for) issuance of common shares	8,300	967	1,296
Repurchase of common shares	(18,071)	(1,687)	(99,598)
Distributions to noncontrolling interest	(7,272)
Noncontrolling interest contribution	20,000		3,972
Reduction in long-term debt	(381,814)	(493,612)	(27,478)
Dividends to shareholders	(68,503)	(50,924)	(69,363)
Proceeds from (payment for) commercial paper, net	40,000	(8,000)	(525,119)
Cash proceeds from equity component of exchangeable debt	159,952
Proceeds from term loan			625,000
Payments on term loan	(162,500)	(162,500)	(300,000)
Redeemable noncontrolling interest contribution	61,123
Proceeds from (payments for) short-term borrowings	(543)	(6,211)	318
Purchase of capped call hedge transactions	(40,250)
Other	(8,211)	(4,732)	(7,767)
Net cash (used for) provided by financing activities	512,180	(138,216)	(849,941)
Effect of exchange rate changes on cash and cash equivalents	(29)	(2,003)	(25,785)
Net increase (decrease) in cash and cash equivalents	72,904	9,563	(246,619)
Cash and cash equivalents, beginning of period	264,093	254,530	501,149
Cash and cash equivalents, end of period	$ 336,997	$ 264,093	$ 254,530