CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income (loss)	$ (612,726)	$ (540,633)	$ (1,029,607)
Adjustments to net income (loss):
Depreciation and amortization	868,509	845,439	874,296
Deferred income tax expense (benefit)	71,579	9,096	(206,670)
Impairments and other charges	62,578	42,188	236,745
Amortization of debt discount and deferred financing costs	32,213	27,583	6,455
Losses (gains) on debt buyback	5,268	16,005	(6,665)
Losses (gains) on long-lived assets, net	95,741	19,064	85,064
Losses (gains) on investments, net	14,195	972
Provision (recovery) of bad debt	1,285	3,083	(3,540)
Impairments on equity method holdings			216,242
Share-based compensation	26,396	31,896	32,000
Foreign currency transaction losses (gains), net	4,235	1,604	5,669
Noncontrolling interest	(28,222)	(6,178)	(135)
Equity in (earnings) losses of unconsolidated affiliates, net of dividends	164	(7)	221,914
Other	720	636	4,527
Changes in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable	(66,486)	(168,436)	253,940
Inventory	(13,981)	(17,444)	40,647
Other current assets	31,770	16,518	37,904
Other long-term assets	11,717	28,772	98
Trade accounts payable and accrued liabilities	(76,561)	79,204	(180,200)
Income taxes payable	(41,939)	14,811	(46,576)
Other long-term liabilities	(60,682)	(341,417)	(10,203)
Net cash (used for) provided by operating activities	325,773	62,756	531,905
Cash flows from investing activities:
Purchases of investments	(676)	(6,722)	(24)
Sales and maturities of investments	4,287	13,069	739
Cash paid for acquisition of businesses, net of cash acquired	(20,859)	12,319	(22,278)
Capital expenditures	(458,938)	(574,467)	(395,455)
Proceeds from sales of assets and insurance claims	109,098	57,933	34,831
Net cash (used for) provided by investing activities	(367,088)	(497,868)	(382,187)
Cash flows from financing activities:
Proceeds from issuance of long-term debt	800,000	411,200	600,000
Debt issuance costs	(21,277)	(11,043)	(11,520)
Proceeds from revolving credit facilities	1,135,000	725,000	611,500
Reduction in revolving credit facilities	(1,475,000)	(215,000)	(611,500)
Proceeds from issuance of common shares, net of issuance costs	301,404	8,300	967
Proceeds from issuance of preferred stock, net of issuance costs	277,927
Distributions to noncontrolling interest	(5,452)	(7,272)
Noncontrolling interest contribution		20,000
Reduction in long-term debt	(878,278)	(381,814)	(493,612)
Dividends to common and preferred shareholders	(87,098)	(68,503)	(50,924)
Proceeds from (payment for) commercial paper	(40,000)	40,000	(8,000)
Cash proceeds (payments) from equity component of exchangeable debt		159,952
Repurchase of common shares		(18,071)	(1,687)
Payments on term loan		(162,500)	(162,500)
Redeemable noncontrolling interest contribution	156,935	61,123
Proceeds from (payments for) short-term borrowings	380	(543)	(6,211)
Purchase of capped call hedge transactions		(40,250)
Other	(8,912)	(8,399)	(4,729)
Net cash provided by financing activities	155,629	512,180	(138,216)
Effect of exchange rate changes on cash and cash equivalents	(5,263)	(29)	(2,003)
Net increase (decrease) in cash and cash equivalents and restricted cash	109,051	77,039	9,499
Cash and cash equivalents and restricted cash, beginning of period	342,029	264,990	255,491
Cash and cash equivalents and restricted cash, end of period	451,080	342,029	264,990
RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH
Cash and cash equivalents, beginning of period	336,997	264,093	254,530
Restricted cash, beginning of period	5,032	897	961
Cash and cash equivalents and restricted cash, beginning of period	342,029	264,990	255,491
Cash and cash equivalents, end of period	447,766	336,997	264,093
Restricted cash, end of period	3,314	5,032	897
Cash and cash equivalents and restricted cash, end of period	$ 451,080	$ 342,029	$ 264,990