Condensed Consolidating Financial Statements (Income Statement) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Condensed Income Statements, Captions [Line Items]
Revenues, net	$ 648,023	$ 634,646	$ 2,078,757	$ 2,026,057
Operating expenses
Technical and operating (excluding depreciation and amortization)	322,743	338,799	956,200	915,336
Selling, general and administrative	138,688	137,116	464,670	473,760
Depreciation and amortization	20,938	22,282	65,037	63,467
Impairment and related charges	11,036	0	28,148	0
Restructuring expense	1,264	19,312	3,887	19,666
Total operating expenses	494,669	517,509	1,517,942	1,472,229
Operating income	153,354	117,137	560,815	553,828
Other income (expense):
Interest expense, net	(31,810)	(29,204)	(85,768)	(90,566)
Share of affiliates' income	0	0	0	0
Loss on extinguishment of debt	(3,004)	(2,295)	(3,004)	(50,638)
Miscellaneous, net	12,420	2,988	42,448	(22,610)
Nonoperating Income (Expense)	(22,394)	(28,511)	(46,324)	(163,814)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	130,960	88,626	514,491	390,014
Income tax expense	(40,124)	(21,157)	(173,399)	(119,090)
Net income including noncontrolling interests	90,836	67,469	341,092	270,924
Net Income (Loss) Attributable to Noncontrolling Interest	(3,834)	(2,076)	(15,276)	(14,908)
Net Income (Loss) Attributable to Parent	87,002	65,393	325,816	256,016
Consolidation, Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Revenues, net	(3,886)	(2,065)	(11,643)	(6,940)
Operating expenses
Technical and operating (excluding depreciation and amortization)	(831)	(687)	(2,367)	(2,064)
Selling, general and administrative	(3,145)	(1,594)	(9,584)	(4,849)
Depreciation and amortization	0	0	0	0
Impairment and related charges	0		0
Restructuring expense	0	0	0	0
Total operating expenses	(3,976)	(2,281)	(11,951)	(6,913)
Operating income	90	216	308	(27)
Other income (expense):
Interest expense, net	0	0	0	0
Share of affiliates' income	(182,274)	(105,699)	(611,622)	(473,733)
Loss on extinguishment of debt	0	0	0	0
Miscellaneous, net	(90)	(216)	(308)	27
Nonoperating Income (Expense)	(182,364)	(105,915)	(611,930)	(473,706)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	(182,274)	(105,699)	(611,622)	(473,733)
Income tax expense	0	0	0	0
Net income including noncontrolling interests	(182,274)	(105,699)	(611,622)	(473,733)
Net Income (Loss) Attributable to Noncontrolling Interest	0	0	0	0
Net Income (Loss) Attributable to Parent	(182,274)	(105,699)	(611,622)	(473,733)
Parent Company [Member]
Condensed Income Statements, Captions [Line Items]
Revenues, net	0	0	0	0
Operating expenses
Technical and operating (excluding depreciation and amortization)	0	0	0	0
Selling, general and administrative	0	0	0	0
Depreciation and amortization	0	0	0	0
Impairment and related charges	0		0
Restructuring expense	0	0	0	0
Total operating expenses	0	0	0	0
Operating income	0	0	0	0
Other income (expense):
Interest expense, net	(34,403)	(29,250)	(93,548)	(89,992)
Share of affiliates' income	171,490	110,101	592,012	498,281
Loss on extinguishment of debt	(3,004)	(2,295)	(3,004)	(50,638)
Miscellaneous, net	(1,076)	(123)	(1,419)	(373)
Nonoperating Income (Expense)	133,007	78,433	494,041	357,278
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	133,007	78,433	494,041	357,278
Income tax expense	(46,005)	(13,040)	(168,225)	(101,262)
Net income including noncontrolling interests	87,002	65,393	325,816	256,016
Net Income (Loss) Attributable to Noncontrolling Interest	0	0	0	0
Net Income (Loss) Attributable to Parent	87,002	65,393	325,816	256,016
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Revenues, net	494,563	484,704	1,610,247	1,559,188
Operating expenses
Technical and operating (excluding depreciation and amortization)	232,432	251,595	694,336	665,627
Selling, general and administrative	99,481	97,633	335,585	343,526
Depreciation and amortization	10,072	9,965	30,399	29,992
Impairment and related charges	0		0
Restructuring expense	(10)	18,764	2,649	18,806
Total operating expenses	341,975	377,957	1,062,969	1,057,951
Operating income	152,588	106,747	547,278	501,237
Other income (expense):
Interest expense, net	10,543	9,649	30,531	28,481
Share of affiliates' income	10,784	(4,402)	19,610	(24,548)
Loss on extinguishment of debt	0	0	0	0
Miscellaneous, net	(244)	385	2,085	173
Nonoperating Income (Expense)	21,083	5,632	52,226	4,106
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	173,671	112,379	599,504	505,343
Income tax expense	(2,181)	(2,278)	(7,492)	(7,062)
Net income including noncontrolling interests	171,490	110,101	592,012	498,281
Net Income (Loss) Attributable to Noncontrolling Interest	0	0	0	0
Net Income (Loss) Attributable to Parent	171,490	110,101	592,012	498,281
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Revenues, net	157,346	152,007	480,153	473,809
Operating expenses
Technical and operating (excluding depreciation and amortization)	91,142	87,891	264,231	251,773
Selling, general and administrative	42,352	41,077	138,669	135,083
Depreciation and amortization	10,866	12,317	34,638	33,475
Impairment and related charges	11,036		28,148
Restructuring expense	1,274	548	1,238	860
Total operating expenses	156,670	141,833	466,924	421,191
Operating income	676	10,174	13,229	52,618
Other income (expense):
Interest expense, net	(7,950)	(9,603)	(22,751)	(29,055)
Share of affiliates' income	0	0	0	0
Loss on extinguishment of debt	0	0	0	0
Miscellaneous, net	13,830	2,942	42,090	(22,437)
Nonoperating Income (Expense)	5,880	(6,661)	19,339	(51,492)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	6,556	3,513	32,568	1,126
Income tax expense	8,062	(5,839)	2,318	(10,766)
Net income including noncontrolling interests	14,618	(2,326)	34,886	(9,640)
Net Income (Loss) Attributable to Noncontrolling Interest	(3,834)	(2,076)	(15,276)	(14,908)
Net Income (Loss) Attributable to Parent	$ 10,784	$ (4,402)	$ 19,610	$ (24,548)