CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net income (loss)	$ (762,846)	$ (680,510)	$ (612,726)
Adjustments to net income (loss):
Depreciation and amortization	853,697	876,103	868,509
Deferred income tax expense (benefit)	64,717	35,894	71,579
Impairments and other charges	318,582	213,404	62,578
Amortization of debt discount and deferred financing costs	31,238	30,931	32,213
Losses (gains) on debt buyback	(228,274)	(11,468)	5,268
Losses (gains) on long-lived assets, net	64,365	40,346	95,741
Losses (gains) on investments, net	4,286	(1,257)	14,195
Provision (recovery) of bad debt	18,194	20,626	1,285
Share-based compensation	24,638	24,660	26,396
Foreign currency transaction losses (gains), net	13,133	20,876	4,235
Noncontrolling interest	(42,795)	(22,375)	(28,222)
Equity in (earnings) losses from unconsolidated affiliates, net of dividends		5	164
Other	(770)	667	720
Changes in operating assets and liabilities, net of effects from acquisitions:
Accounts receivable	67,502	276,685	(66,486)
Inventory	6,188	(18,695)	(13,981)
Other current assets	38,672	5,157	31,770
Other long-term assets	20,830	13,106	11,717
Trade accounts payable and accrued liabilities	(142,826)	(142,857)	(76,561)
Income taxes payable	(933)	(4,857)	(41,939)
Other long-term liabilities	2,163	8,117	(60,682)
Net cash provided by (used for) operating activities	349,761	684,558	325,773
Cash flows from investing activities:
Purchases of investments	(91)	(4,323)	(676)
Sales and maturities of investments	2,760	18,849	4,287
Cash paid for acquisition of businesses, net of cash acquired		(2,929)	(20,859)
Capital expenditures	(195,523)	(427,741)	(458,938)
Proceeds from sales of assets and insurance claims	27,397	60,288	109,098
Net cash (used for) provided by investing activities	(165,457)	(355,856)	(367,088)
Cash flows from financing activities:
Proceeds from issuance of long-term debt	1,000,000		800,000
Reduction in long-term debt	(1,394,043)	(455,360)	(878,278)
Debt issuance costs	(28,112)	(1,767)	(21,277)
Proceeds from revolving credit facilities	1,552,500	1,050,000	1,135,000
Reduction in revolving credit facilities	(1,235,000)	(865,000)	(1,475,000)
Proceeds from (payment for) commercial paper			(40,000)
Proceeds from (payments for) short-term borrowings		(561)	380
Proceeds from issuance of common shares, net of issuance costs			301,404
Proceeds from issuance of preferred stock, net of issuance costs			277,927
Repurchase of common and preferred shares	(1,731)
Dividends to common and preferred shareholders	(22,538)	(49,583)	(87,098)
Redeemable noncontrolling interest contribution			156,935
Distributions to noncontrolling interest	(5,083)	(4,552)	(5,452)
Other	(13,994)	(4,750)	(8,912)
Net cash (used for) provided by financing activities	(148,001)	(331,573)	155,629
Effect of exchange rate changes on cash and cash equivalents	(3,061)	(6,171)	(5,263)
Net increase (decrease) in cash and cash equivalents and restricted cash	33,242	(9,042)	109,051
Cash and cash equivalents and restricted cash, beginning of period	442,038	451,080	342,029
Cash and cash equivalents and restricted cash, end of period	475,280	442,038	451,080
RECONCILIATION OF CASH AND CASH EQUIVALENTS AND RESTRICTED CASH
Cash and cash equivalents, beginning of period	435,990	447,766	336,997
Restricted cash, beginning of period	6,048	3,314	5,032
Cash and cash equivalents and restricted cash, beginning of period	442,038	451,080	342,029
Cash and cash equivalents, end of period	472,246	435,990	447,766
Restricted cash, end of period	3,034	6,048	3,314
Cash and cash equivalents and restricted cash, end of period	$ 475,280	$ 442,038	$ 451,080