Condensed Consolidating Guarantor Financial Statements - Balance Sheets (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Feb. 25, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 214,007			$ 86,655	$ 69,988		$ 93,699
Accounts receivable, net	570,006			562,214
Due from Related Parties, Current	281			295
Inventories	66,883			49,397
Other Assets, Current	26,403			17,264
Assets, Current	877,580			715,825
Property, plant and equipment (net of accumulated depreciation of $721,958 and $607,903, respectively)	3,927,645			3,457,326
Equity method investments	283,638			274,009
Goodwill	338,856		$ 78,800	257,302
Intangible Assets, Net (Excluding Goodwill)	444,229			365,038
Other noncurrent assets	151,017			140,807
Right-of-Use Asset, Operating and Finance Leases	89,665			0
Assets	6,112,630			5,210,307
Current liabilities:
Accounts Payable	502,736			494,792
Due to Related Parties	870			3,715
Accrued liabilities	113,693			115,095
Other current liabilities including deferred revenue and current portion of long-term debt	32,030			23,555
Liabilities, Current	649,329			637,157
Long-term debt	2,477,326			2,278,834
Deferred income taxes	132,980			55,789
Other Liabilities, Noncurrent	141,632			38,548
Commitments and Contingencies
Redeemable preferred stock, $0.01 par value, $386,988 liquidation preference (authorized - 4,000 shares; issued - 350 shares)	379,285			359,658
Subsidiary Preferred Stock, Value Outstanding	258,376			0
Stockholders' Equity Attributable to Parent	1,247,859			1,490,832
Stockholders' Equity Attributable to Noncontrolling Interest	825,843			349,489
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	2,073,702	$ 2,117,346		1,840,321	1,555,985	$ 1,584,518	1,658,365
Liabilities and Equity	6,112,630			5,210,307
Consolidation, Eliminations [Member]
Current assets:
Cash and cash equivalents	(3,132)			(4,151)	(2,704)		(8,630)
Accounts receivable, net	0			0
Due from Related Parties, Current	0			0
Inventories	0			0
Other Assets, Current	(34)			0
Assets, Current	(3,166)			(4,151)
Property, plant and equipment (net of accumulated depreciation of $721,958 and $607,903, respectively)	0			0
Equity method investments	(4,035,618)			(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
Assets	(4,038,784)			(4,551,083)
Current liabilities:
Accounts Payable	0			0
Due to Related Parties	0			0
Accrued liabilities	3			2
Other current liabilities including deferred revenue and current portion of long-term debt	0			0
Liabilities, Current	3			2
Long-term debt	(6,098)			(6,315)
Deferred income taxes	0			0
Other Liabilities, Noncurrent	0			0
Commitments and Contingencies
Redeemable preferred stock, $0.01 par value, $386,988 liquidation preference (authorized - 4,000 shares; issued - 350 shares)	0			0
Subsidiary Preferred Stock, Value Outstanding	0
Stockholders' Equity Attributable to Parent	(4,032,689)			(4,544,770)
Stockholders' Equity Attributable to Noncontrolling Interest	0			0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	(4,032,689)			(4,544,770)
Liabilities and Equity	(4,038,784)			(4,551,083)
Reportable Legal Entities [Member] | Parent Company [Member]
Current assets:
Cash and cash equivalents	204,474			40,064	21,397		32,457
Accounts receivable, net	2			83
Due from Related Parties, Current	129			120
Inventories	0			0
Other Assets, Current	7,459			6,682
Assets, Current	212,064			46,949
Property, plant and equipment (net of accumulated depreciation of $721,958 and $607,903, respectively)	6,713			6,732
Equity method investments	2,811,088			3,267,581
Goodwill	0			0
Intangible Assets, Net (Excluding Goodwill)	1			5
Other noncurrent assets	44,114			41,981
Right-of-Use Asset, Operating and Finance Leases	6,133
Assets	3,080,113			3,363,248
Current liabilities:
Accounts Payable	3,274			38
Due to Related Parties	0			1
Accrued liabilities	26,118			33,239
Other current liabilities including deferred revenue and current portion of long-term debt	4,961			5,723
Liabilities, Current	34,353			39,001
Long-term debt	1,351,079			1,467,083
Deferred income taxes	61,601			4,882
Other Liabilities, Noncurrent	5,936			1,792
Commitments and Contingencies
Redeemable preferred stock, $0.01 par value, $386,988 liquidation preference (authorized - 4,000 shares; issued - 350 shares)	379,285			359,658
Subsidiary Preferred Stock, Value Outstanding	0
Stockholders' Equity Attributable to Parent	1,247,859			1,490,832
Stockholders' Equity Attributable to Noncontrolling Interest	0			0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	1,247,859			1,490,832
Liabilities and Equity	3,080,113			3,363,248
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	0			0	0		0
Accounts receivable, net	444,803			461,980
Due from Related Parties, Current	1			18
Inventories	66,883			49,397
Other Assets, Current	11,367			6,711
Assets, Current	523,054			518,106
Property, plant and equipment (net of accumulated depreciation of $721,958 and $607,903, respectively)	946,468			992,974
Equity method investments	1,508,168			1,553,360
Goodwill	0			0
Intangible Assets, Net (Excluding Goodwill)	113,433			119,583
Other noncurrent assets	4,196			4,788
Right-of-Use Asset, Operating and Finance Leases	3,316
Assets	3,098,635			3,188,811
Current liabilities:
Accounts Payable	444,373			444,984
Due to Related Parties	870			3,714
Accrued liabilities	15,582			18,424
Other current liabilities including deferred revenue and current portion of long-term debt	2,717			3,409
Liabilities, Current	463,542			470,531
Long-term debt	6,098			6,315
Deferred income taxes	0			0
Other Liabilities, Noncurrent	3,883			0
Commitments and Contingencies
Redeemable preferred stock, $0.01 par value, $386,988 liquidation preference (authorized - 4,000 shares; issued - 350 shares)	0			0
Subsidiary Preferred Stock, Value Outstanding	0
Stockholders' Equity Attributable to Parent	2,625,112			2,711,965
Stockholders' Equity Attributable to Noncontrolling Interest	0			0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	2,625,112			2,711,965
Liabilities and Equity	3,098,635			3,188,811
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	12,665			50,742	$ 51,295		$ 69,872
Accounts receivable, net	125,201			100,151
Due from Related Parties, Current	151			157
Inventories	0			0
Other Assets, Current	7,611			3,871
Assets, Current	145,628			154,921
Property, plant and equipment (net of accumulated depreciation of $721,958 and $607,903, respectively)	2,974,464			2,457,620
Equity method investments	0			0
Goodwill	338,856			257,302
Intangible Assets, Net (Excluding Goodwill)	330,795			245,450
Other noncurrent assets	102,707			94,038
Right-of-Use Asset, Operating and Finance Leases	80,216
Assets	3,972,666			3,209,331
Current liabilities:
Accounts Payable	55,089			49,770
Due to Related Parties	0			0
Accrued liabilities	71,990			63,430
Other current liabilities including deferred revenue and current portion of long-term debt	24,352			14,423
Liabilities, Current	151,431			127,623
Long-term debt	1,126,247			811,751
Deferred income taxes	71,379			50,907
Other Liabilities, Noncurrent	131,813			36,756
Commitments and Contingencies
Redeemable preferred stock, $0.01 par value, $386,988 liquidation preference (authorized - 4,000 shares; issued - 350 shares)	0			0
Subsidiary Preferred Stock, Value Outstanding	258,376
Stockholders' Equity Attributable to Parent	1,407,577			1,832,805
Stockholders' Equity Attributable to Noncontrolling Interest	825,843			349,489
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	2,233,420			2,182,294
Liabilities and Equity	$ 3,972,666			$ 3,209,331