Condensed Consolidating Guarantor Financial Statements - Balance Sheets (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Mar. 31, 2019	Feb. 25, 2019	Dec. 31, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 252,927			$ 86,655	$ 55,324		$ 93,699
Accounts receivable, net	690,705			562,214
Due from Related Parties, Current	1,182			295
Inventories	63,539			49,397
Disposal Group, Including Discontinued Operation, Assets, Current	1,025			0
Other Assets, Current	33,984			17,264
Assets, Current	1,043,362			715,825
Property, plant and equipment (net of accumulated depreciation of $692,081 and $607,903, respectively)	3,886,438			3,457,326
Equity method investments	284,186			274,009
Goodwill	338,931		$ 78,800	257,302
Intangible Assets, Net (Excluding Goodwill)	455,858			365,038
Other noncurrent assets	150,539			140,807
Right-of-Use Asset, Operating and Finance Leases	93,089			0
Disposal Group, Including Discontinued Operation, Assets, Noncurrent	5,537			0
Assets	6,257,940			5,210,307
Current liabilities:
Accounts Payable	580,254			494,792
Due to Related Parties	3,242			3,715
Accrued liabilities	104,830			115,095
Disposal Group, Including Discontinued Operation, Liabilities, Current	1,935			0
Other current liabilities including deferred revenue and current portion of long-term debt	30,383			23,555
Liabilities, Current	720,644			637,157
Long-term debt	2,510,897			2,278,834
Deferred income taxes	137,846			55,789
Other Liabilities, Noncurrent	145,703			38,548
Commitments and Contingencies
Redeemable preferred stock, $0.01 par value, $380,331 liquidation preference (authorized - 4,000 shares; issued - 350 shares)	372,628			359,658
Subsidiary Preferred Stock, Value Outstanding	252,876			0
Stockholders' Equity Attributable to Parent	1,306,006			1,490,832
Stockholders' Equity Attributable to Noncontrolling Interest	811,340			349,489
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	2,117,346	$ 2,130,487		1,840,321	1,584,518	$ 1,620,163	1,658,365
Liabilities and Equity	6,257,940			5,210,307
Consolidation, Eliminations [Member]
Current assets:
Cash and cash equivalents	(514)			(4,151)	(2,204)		(8,630)
Accounts receivable, net	(27)			0
Due from Related Parties, Current	0			0
Inventories	0			0
Disposal Group, Including Discontinued Operation, Assets, Current	0
Other Assets, Current	0			0
Assets, Current	(541)			(4,151)
Property, plant and equipment (net of accumulated depreciation of $692,081 and $607,903, respectively)	0			0
Equity method investments	(4,117,190)			(4,546,932)
Goodwill	0			0
Intangible Assets, Net (Excluding Goodwill)	0			0
Other noncurrent assets	0			0
Right-of-Use Asset, Operating and Finance Leases	0
Disposal Group, Including Discontinued Operation, Assets, Noncurrent	0
Assets	(4,117,731)			(4,551,083)
Current liabilities:
Accounts Payable	(27)			0
Due to Related Parties	0			0
Accrued liabilities	(5)			2
Disposal Group, Including Discontinued Operation, Liabilities, Current	0
Other current liabilities including deferred revenue and current portion of long-term debt	0			0
Liabilities, Current	(32)			2
Long-term debt	(6,293)			(6,315)
Deferred income taxes	0			0
Other Liabilities, Noncurrent	0			0
Commitments and Contingencies
Redeemable preferred stock, $0.01 par value, $380,331 liquidation preference (authorized - 4,000 shares; issued - 350 shares)	0			0
Subsidiary Preferred Stock, Value Outstanding	0
Stockholders' Equity Attributable to Parent	(4,111,406)			(4,544,770)
Stockholders' Equity Attributable to Noncontrolling Interest	0			0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	(4,111,406)			(4,544,770)
Liabilities and Equity	(4,117,731)			(4,551,083)
Reportable Legal Entities [Member] | Parent Company [Member]
Current assets:
Cash and cash equivalents	220,203			40,064	16,146		32,457
Accounts receivable, net	0			83
Due from Related Parties, Current	1,056			120
Inventories	0			0
Disposal Group, Including Discontinued Operation, Assets, Current	0
Other Assets, Current	7,314			6,682
Assets, Current	228,573			46,949
Property, plant and equipment (net of accumulated depreciation of $692,081 and $607,903, respectively)	6,930			6,732
Equity method investments	2,857,808			3,267,581
Goodwill	0			0
Intangible Assets, Net (Excluding Goodwill)	2			5
Other noncurrent assets	41,822			41,981
Right-of-Use Asset, Operating and Finance Leases	6,706
Disposal Group, Including Discontinued Operation, Assets, Noncurrent	0
Assets	3,141,841			3,363,248
Current liabilities:
Accounts Payable	237			38
Due to Related Parties	0			1
Accrued liabilities	34,268			33,239
Disposal Group, Including Discontinued Operation, Liabilities, Current	0
Other current liabilities including deferred revenue and current portion of long-term debt	3,960			5,723
Liabilities, Current	38,465			39,001
Long-term debt	1,349,907			1,467,083
Deferred income taxes	68,351			4,882
Other Liabilities, Noncurrent	6,484			1,792
Commitments and Contingencies
Redeemable preferred stock, $0.01 par value, $380,331 liquidation preference (authorized - 4,000 shares; issued - 350 shares)	372,628			359,658
Subsidiary Preferred Stock, Value Outstanding	0
Stockholders' Equity Attributable to Parent	1,306,006			1,490,832
Stockholders' Equity Attributable to Noncontrolling Interest	0			0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	1,306,006			1,490,832
Liabilities and Equity	3,141,841			3,363,248
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	0			0	0		0
Accounts receivable, net	555,927			461,980
Due from Related Parties, Current	2			18
Inventories	63,539			49,397
Disposal Group, Including Discontinued Operation, Assets, Current	0
Other Assets, Current	15,581			6,711
Assets, Current	635,049			518,106
Property, plant and equipment (net of accumulated depreciation of $692,081 and $607,903, respectively)	959,909			992,974
Equity method investments	1,543,568			1,553,360
Goodwill	0			0
Intangible Assets, Net (Excluding Goodwill)	115,483			119,583
Other noncurrent assets	4,046			4,788
Right-of-Use Asset, Operating and Finance Leases	6,174
Disposal Group, Including Discontinued Operation, Assets, Noncurrent	0
Assets	3,264,229			3,188,811
Current liabilities:
Accounts Payable	532,231			444,984
Due to Related Parties	3,242			3,714
Accrued liabilities	14,529			18,424
Disposal Group, Including Discontinued Operation, Liabilities, Current	0
Other current liabilities including deferred revenue and current portion of long-term debt	9,431			3,409
Liabilities, Current	559,433			470,531
Long-term debt	6,293			6,315
Deferred income taxes	0			0
Other Liabilities, Noncurrent	6,190			0
Commitments and Contingencies
Redeemable preferred stock, $0.01 par value, $380,331 liquidation preference (authorized - 4,000 shares; issued - 350 shares)	0			0
Subsidiary Preferred Stock, Value Outstanding	0
Stockholders' Equity Attributable to Parent	2,692,313			2,711,965
Stockholders' Equity Attributable to Noncontrolling Interest	0			0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	2,692,313			2,711,965
Liabilities and Equity	3,264,229			3,188,811
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	33,238			50,742	$ 41,382		$ 69,872
Accounts receivable, net	134,805			100,151
Due from Related Parties, Current	124			157
Inventories	0			0
Disposal Group, Including Discontinued Operation, Assets, Current	1,025
Other Assets, Current	11,089			3,871
Assets, Current	180,281			154,921
Property, plant and equipment (net of accumulated depreciation of $692,081 and $607,903, respectively)	2,919,599			2,457,620
Equity method investments	0			0
Goodwill	338,931			257,302
Intangible Assets, Net (Excluding Goodwill)	340,373			245,450
Other noncurrent assets	104,671			94,038
Right-of-Use Asset, Operating and Finance Leases	80,209
Disposal Group, Including Discontinued Operation, Assets, Noncurrent	5,537
Assets	3,969,601			3,209,331
Current liabilities:
Accounts Payable	47,813			49,770
Due to Related Parties	0			0
Accrued liabilities	56,038			63,430
Disposal Group, Including Discontinued Operation, Liabilities, Current	1,935
Other current liabilities including deferred revenue and current portion of long-term debt	16,992			14,423
Liabilities, Current	122,778			127,623
Long-term debt	1,160,990			811,751
Deferred income taxes	69,495			50,907
Other Liabilities, Noncurrent	133,029			36,756
Commitments and Contingencies
Redeemable preferred stock, $0.01 par value, $380,331 liquidation preference (authorized - 4,000 shares; issued - 350 shares)	0			0
Subsidiary Preferred Stock, Value Outstanding	252,876
Stockholders' Equity Attributable to Parent	1,419,093			1,832,805
Stockholders' Equity Attributable to Noncontrolling Interest	811,340			349,489
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	2,230,433			2,182,294
Liabilities and Equity	$ 3,969,601			$ 3,209,331