CONDENSED COMBINED DEBTOR-IN-POSSESSION FINANCIAL INFORMATION - Debtors' Statement Cash Flow (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Cash Flow Statements, Captions [Line Items]
Consolidated net income (loss)	$ 224,908	$ 71,783	$ (66,290)	$ (433,040)	$ 350,477	$ (248,831)	$ (170,883)	$ (389,474)	$ (202,639)	$ (458,711)	$ (246,572)
Impairment charges	0	40,922	0	0	2,568	7,631	0	0	40,922	10,199	8,000
Depreciation and amortization	111,125	120,700	147,644	151,434	157,645	149,749	147,795	146,106	530,903	601,295	635,227
Deferred taxes									18,038	(488,190)	(97,416)
Provision for doubtful accounts									28,429	38,944	27,390
Amortization of deferred financing charges and note discounts, net									22,601	57,474	69,951
Non-cash Reorganization items, net									252,392	0	0
Share-based compensation									10,583	12,078	13,133
Loss on disposal of operating and other assets									131	44,461	365,710
Equity in earnings (loss) of nonconsolidated affiliates	729	172	(38)	157	(615)	(2,238)	240	(242)	1,020	(2,855)	(16,733)
Gain on extinguishment of debt	0	$ 0	$ 0	100	1,271	$ 0	$ 0	0	100	1,271	157,556
Barter and trade income									15,733	42,210	38,323
Other reconciling items, net									(36,860)	23,576	(84,350)
Increase in accounts receivable									110,062	149,347	14,469
Increase in prepaid expenses and other current assets									(22)	28,377	3,114
Increase (decrease) in accrued expenses									40,075	4,133	(2,862)
Increase (decrease) in accounts payable									38,265	15,736	3,065
Increase in accrued interest									304,729	41,006	20,809
Increase (decrease) in deferred income									19,892	(26,533)	23,661
Changes in other operating assets and liabilities									47,354	12,254	(7,938)
Net cash provided by (used for) operating activities									966,672	(491,210)	(15,765)
Purchases of businesses									(74,272)	0	(500)
Capital expenditures									296,324	291,966	314,717
Proceeds from disposal of assets									10,422	82,987	856,981
Purchases of other operating assets									2,138	1,213	4,414
Change in other, net									1,243	4,060	2,771
Net cash used for investing activities									(345,478)	(214,692)	533,496
Draws on revolving credit facilities									143,332	100,000	100,000
Payments on credit facilities									258,308	25,909	2,100
Payments on long-term debt									365,001	9,946	421,263
Change in other, net									(2,401)	(22,333)	(12,093)
Net cash provided by (used for) financing activities									(491,799)	151,335	(418,231)
Effect of exchange rate changes on cash									(10,361)	10,141	(5,639)
Net increase in cash, cash equivalents and restricted cash									119,034	(544,426)	93,861
Cash, cash equivalents and restricted cash at beginning of period				311,300				$ 855,726	311,300	855,726	761,865
Cash, cash equivalents and restricted cash at end of period	430,334				311,300				430,334	311,300	$ 855,726
Debtors
Condensed Cash Flow Statements, Captions [Line Items]
Consolidated net income (loss)									8,016
Impairment charges									33,151
Depreciation and amortization									210,914
Deferred taxes									3,643
Provision for doubtful accounts									21,003
Amortization of deferred financing charges and note discounts, net									11,871
Non-cash Reorganization items, net									252,392
Share-based compensation									2,066
Loss on disposal of operating and other assets									(3,224)
Equity in earnings (loss) of nonconsolidated affiliates									(140)
Gain on extinguishment of debt									5,667
Barter and trade income									10,873
Other reconciling items, net									273
Increase in accounts receivable									35,771
Increase in prepaid expenses and other current assets									2,034
Increase (decrease) in accrued expenses									14,782
Increase (decrease) in accounts payable									8,962
Increase in accrued interest									303,495
Increase (decrease) in deferred income									(14,963)
Changes in other operating assets and liabilities									25,483
Net cash provided by (used for) operating activities									778,595
Purchases of businesses									(74,272)
Capital expenditures									85,012
Proceeds from disposal of assets									642
Purchases of other operating assets									305
Change in other, net									132
Net cash used for investing activities									(159,079)
Draws on revolving credit facilities									143,332
Payments on credit facilities									258,308
Payments on long-term debt									358,911
Net transfers to related parties									65,666
Change in other, net									(79)
Net cash provided by (used for) financing activities									(539,632)
Effect of exchange rate changes on cash									0
Net increase in cash, cash equivalents and restricted cash									79,884
Cash, cash equivalents and restricted cash at beginning of period				$ 102,468					102,468
Cash, cash equivalents and restricted cash at end of period	$ 182,352				$ 102,468				$ 182,352	$ 102,468