Condensed Consolidating Guarantor Financial Statements - Balance Sheets (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014
Condensed Balance Sheet Statements, Captions [Line Items]
Other Liabilities, Current	$ 17,462	$ 13,281
Current assets:
Cash and cash equivalents	163,748	58,096	$ 145,993	$ 40,598
Restricted cash	0	32
Accounts receivable, net	335,256	326,713
Receivable from affiliates	4,542	5,914
Inventories	83,473	70,239
Other current assets	25,465	19,387
Total current assets	612,484	480,381
Property, plant and equipment, net	1,696,010	1,566,821
Equity method investments	438,194	551,078
Goodwill	34,475	48,032
Other intangible assets, net	153,796	162,223
Other noncurrent assets	51,573	45,374
Total assets	2,986,532	2,853,909
Current liabilities:
Accounts Payable	294,167	273,666
Due to Related Parties	5,791	5,033
Accrued Liabilities	98,347	85,047
Total current liabilities	415,767	377,027
Long-term debt, net	1,030,140	1,057,816
Deferred income taxes	49,361	200,953
Other noncurrent liabilities	23,932	21,757
Commitments and contingencies
Owners’ equity excluding noncontrolling interests in consolidated subsidiaries	1,467,332	1,115,527
Noncontrolling interests in consolidated subsidiaries	0	80,829
Total owners’ equity	1,467,332	1,196,356
Total liabilities and owners’ equity	2,986,532	2,853,909
Parent Company [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Other Liabilities, Current	783	569
Current assets:
Cash and cash equivalents	98,435	4,559	40,950	9,254
Restricted cash		0
Accounts receivable, net	691	640
Receivable from affiliates	1,947	1,616
Inventories	0	0
Other current assets	8,944	8,477
Total current assets	110,017	15,292
Property, plant and equipment, net	5,066	4,335
Equity method investments	2,368,606	1,546,853
Goodwill	0	0
Other intangible assets, net	16	20
Other noncurrent assets	48,408	39,358
Total assets	2,532,113	1,605,858
Current liabilities:
Accounts Payable	215	734
Due to Related Parties	199	78
Accrued Liabilities	29,566	5,551
Total current liabilities	30,763	6,932
Long-term debt, net	1,030,108	325,460
Deferred income taxes	1,670	155,411
Other noncurrent liabilities	2,240	2,528
Commitments and contingencies
Owners’ equity excluding noncontrolling interests in consolidated subsidiaries	1,467,332	1,115,527
Noncontrolling interests in consolidated subsidiaries		0
Total owners’ equity	1,467,332	1,115,527
Total liabilities and owners’ equity	2,532,113	1,605,858
Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Other Liabilities, Current	9,600	4,246
Current assets:
Cash and cash equivalents	0	9,058	44,010	3,624
Restricted cash		0
Accounts receivable, net	277,944	260,621
Receivable from affiliates	4,361	7,063
Inventories	76,935	59,073
Other current assets	13,668	5,243
Total current assets	372,908	341,058
Property, plant and equipment, net	969,311	978,224
Equity method investments	853,042	770,742
Goodwill	26,628	39,680
Other intangible assets, net	152,189	159,750
Other noncurrent assets	1,883	4,775
Total assets	2,375,961	2,294,229
Current liabilities:
Accounts Payable	270,095	254,785
Due to Related Parties	10,326	13,151
Accrued Liabilities	23,758	33,199
Total current liabilities	313,779	305,381
Long-term debt, net	6,463	739,696
Deferred income taxes	0	0
Other noncurrent liabilities	0	0
Commitments and contingencies
Owners’ equity excluding noncontrolling interests in consolidated subsidiaries	2,055,719	1,168,323
Noncontrolling interests in consolidated subsidiaries		80,829
Total owners’ equity	2,055,719	1,249,152
Total liabilities and owners’ equity	2,375,961	2,294,229
Non-Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Other Liabilities, Current	7,079	8,466
Current assets:
Cash and cash equivalents	67,345	46,043	64,618	31,821
Restricted cash		32
Accounts receivable, net	56,621	65,452
Receivable from affiliates	2,968	5,430
Inventories	6,538	11,166
Other current assets	2,853	5,667
Total current assets	136,325	133,790
Property, plant and equipment, net	721,633	584,262
Equity method investments	0	0
Goodwill	7,847	8,352
Other intangible assets, net	1,591	2,453
Other noncurrent assets	1,282	1,241
Total assets	868,678	730,098
Current liabilities:
Accounts Payable	23,857	18,147
Due to Related Parties	0	0
Accrued Liabilities	45,018	46,293
Total current liabilities	75,954	72,906
Long-term debt, net	16,500	16,500
Deferred income taxes	47,691	45,542
Other noncurrent liabilities	21,692	19,229
Commitments and contingencies
Owners’ equity excluding noncontrolling interests in consolidated subsidiaries	706,841	575,921
Noncontrolling interests in consolidated subsidiaries		0
Total owners’ equity	706,841	575,921
Total liabilities and owners’ equity	868,678	730,098
Consolidating Adjustments [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Other Liabilities, Current	0	0
Current assets:
Cash and cash equivalents	(2,032)	(1,564)	$ (3,585)	$ (4,101)
Restricted cash		0
Accounts receivable, net	0	0
Receivable from affiliates	(4,734)	(8,195)
Inventories	0	0
Other current assets	0	0
Total current assets	(6,766)	(9,759)
Property, plant and equipment, net	0	0
Equity method investments	(2,783,454)	(1,766,517)
Goodwill	0	0
Other intangible assets, net	0	0
Other noncurrent assets	0	0
Total assets	(2,790,220)	(1,776,276)
Current liabilities:
Accounts Payable	0	0
Due to Related Parties	(4,734)	(8,196)
Accrued Liabilities	5	4
Total current liabilities	(4,729)	(8,192)
Long-term debt, net	(22,931)	(23,840)
Deferred income taxes	0	0
Other noncurrent liabilities	0	0
Commitments and contingencies
Owners’ equity excluding noncontrolling interests in consolidated subsidiaries	(2,762,560)	(1,744,244)
Noncontrolling interests in consolidated subsidiaries		0
Total owners’ equity	(2,762,560)	(1,744,244)
Total liabilities and owners’ equity	$ (2,790,220)	$ (1,776,276)