CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) shares in Thousands, $ 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
Income Statement [Abstract]
Revenue	$ 1,772,525	$ 1,582,765	$ 1,600,842	$ 1,369,648	$ 1,713,161	$ 1,536,757	$ 1,589,637	$ 1,328,876	$ 6,325,780	$ 6,168,431	$ 6,251,000
Operating expenses:
Direct operating expenses (excludes depreciation and amortization)	663,688	630,264	636,641	602,355	656,219	623,741	616,221	572,543	2,532,948	2,468,724	2,395,037
Selling, general and administrative expenses (excludes depreciation and amortization)	514,269	457,757	451,490	472,987	505,131	438,796	447,509	450,786	1,896,503	1,842,222	1,726,118
Corporate expenses (excludes depreciation and amortization)	94,665	84,193	79,626	78,734	78,411	77,967	77,158	78,362	337,218	311,898	341,072
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
Impairment charges	0	40,922	0	0	2,568	7,631	0	0	40,922	10,199	8,000
Other operating income (expense), net	(1,556)	(1,637)	(289)	(3,286)	10,919	(13,215)	6,916	31,084	(6,768)	35,704	353,556
Operating income (loss)	387,222	247,292	285,152	60,852	324,106	225,658	307,870	112,163	980,518	969,797	1,499,102
Interest expense (excludes contractual interest of $1,189,132 for the year ended December 31, 2018)	97,679	99,255	107,600	418,397	475,317	470,250	463,232	455,337	722,931	1,864,136	1,850,119
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
Other expense, net	(23,352)	(6,182)	(28,279)	(1,063)	(6,517)	50	1,647	(15,374)	(58,876)	(20,194)	(86,009)
Reorganization items, net	42,849	52,475	68,740	192,055	0	0	0	0	356,119	0	0
Income (loss) before income taxes	224,071	89,552	80,495	(550,406)	(157,072)	(246,780)	(153,475)	(358,790)	(156,288)	(916,117)	(296,203)
Income tax benefit (expense)	837	(17,769)	(146,785)	117,366	507,549	(2,051)	(17,408)	(30,684)	(46,351)	457,406	49,631
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)
Less amount attributable to noncontrolling interest	10,003	1,705	3,609	(16,046)	(68,265)	1,659	5,591	364	(729)	(60,651)	55,484
Net income (loss) attributable to the Company	$ 214,905	$ 70,078	$ (69,899)	$ (416,994)	$ 418,742	$ (250,490)	$ (176,474)	$ (389,838)	(201,910)	(398,060)	(302,056)
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments									(15,924)	43,851	22,932
Other adjustments to comprehensive income (loss)									(1,498)	6,306	(12,390)
Reclassification adjustments									2,962	5,441	46,730
Other comprehensive income (loss)									(14,460)	55,598	57,272
Comprehensive income (loss)									(216,370)	(342,462)	(244,784)
Less amount attributable to noncontrolling interest									(8,713)	13,847	(1,787)
Comprehensive income (loss) attributable to the Company									$ (207,657)	$ (356,309)	$ (242,997)
Net loss attributable to the Company per common share:
Basic (in dollars per share)	$ 2.51	$ 0.82	$ (0.82)	$ (4.89)	$ 4.92	$ (2.94)	$ (2.08)	$ (4.60)	$ (2.36)	$ (4.68)	$ (3.57)
Weighted average common shares outstanding - Basic (in shares)									85,412	84,967	84,569
Diluted (in dollars per share)	$ 2.51	$ 0.82	$ (0.82)	$ (4.89)	$ 4.88	$ (2.94)	$ (2.08)	$ (4.60)	$ (2.36)	$ (4.68)	$ (3.57)
Weighted average common shares outstanding - Diluted (in shares)									85,412	84,967	84,569