Condensed Consolidating Guarantor Financial Statements - Balance Sheets (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 228,783	$ 40,598	$ 75,338	$ 79,351
Restricted cash	34	6,980
Accounts receivable, net	349,931	351,334
Receivable from affiliates	18,172	16,819
Inventories	77,677	43,532
Other current assets	20,560	20,017
Total current assets	695,157	479,280
Property, plant and equipment, net	1,420,194	1,256,825
Equity method investments	548,831	577,920
Goodwill	58,023	58,326
Other intangible assets, net	167,689	173,065
Other noncurrent assets, net	59,495	44,386
Total assets	2,949,389	2,589,802
Current liabilities:
Accounts payable	278,903	257,177
Payable to affiliates	19,040	13,460
Accrued liabilities	99,393	92,694
Payables to pre-petition creditors	0	3,129
Deferred revenue	21,071	23,688
Other current liabilities	1,694	1,474
Current portion of long-term debt	44	40
Total current liabilities	420,145	391,662
Long-term debt	1,044,339	767,092
Deferred income taxes	191,171	161,956
Other noncurrent liabilities	$ 22,099	$ 49,655
Commitments and contingencies
Owners’ equity excluding noncontrolling interests in consolidated subsidiaries	$ 1,173,297	$ 1,149,508
Noncontrolling interests in consolidated subsidiaries	98,338	69,929
Total owners’ equity	1,271,635	1,219,437
Total liabilities and owners’ equity	2,949,389	2,589,802
Parent Company [Member]
Current assets:
Cash and cash equivalents	118,060	9,254	6,825	2,545
Restricted cash	0	3,856
Accounts receivable, net	641	9,669
Receivable from affiliates	1,545	2,512
Inventories	0	0
Other current assets	8,464	10,498
Total current assets	128,710	35,789
Property, plant and equipment, net	4,597	4,112
Equity method investments	1,464,091	1,551,825
Goodwill	0	0
Other intangible assets, net	23	26
Other noncurrent assets, net	33,488	24,555
Total assets	1,630,909	1,616,307
Current liabilities:
Accounts payable	1,005	649
Payable to affiliates	11	21
Accrued liabilities	9,160	11,993
Payables to pre-petition creditors		3,129
Deferred revenue	0	0
Other current liabilities	1,071	224
Current portion of long-term debt	0	0
Total current liabilities	11,247	16,016
Long-term debt	300,000	335,000
Deferred income taxes	143,978	112,897
Other noncurrent liabilities	$ 2,387	$ 2,886
Commitments and contingencies
Owners’ equity excluding noncontrolling interests in consolidated subsidiaries	$ 1,173,297	$ 1,149,508
Noncontrolling interests in consolidated subsidiaries	0	0
Total owners’ equity	1,173,297	1,149,508
Total liabilities and owners’ equity	1,630,909	1,616,307
Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	0	0	0	0
Restricted cash	0	0
Accounts receivable, net	24,165	32,056
Receivable from affiliates	2,372	6,624
Inventories	233	248
Other current assets	786	575
Total current assets	27,556	39,503
Property, plant and equipment, net	513,308	452,352
Equity method investments	397,479	348,115
Goodwill	13,052	13,052
Other intangible assets, net	148,283	152,383
Other noncurrent assets, net	2,965	958
Total assets	1,102,643	1,006,363
Current liabilities:
Accounts payable	13,846	22,097
Payable to affiliates	15	7
Accrued liabilities	10,928	17,575
Payables to pre-petition creditors		0
Deferred revenue	0	0
Other current liabilities	0	707
Current portion of long-term debt	0	0
Total current liabilities	24,789	40,386
Long-term debt	0	0
Deferred income taxes	0	0
Other noncurrent liabilities	$ 0	$ 0
Commitments and contingencies
Owners’ equity excluding noncontrolling interests in consolidated subsidiaries	$ 1,077,854	$ 965,977
Noncontrolling interests in consolidated subsidiaries	0	0
Total owners’ equity	1,077,854	965,977
Total liabilities and owners’ equity	1,102,643	1,006,363
Non-Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	112,980	35,445	71,572	78,342
Restricted cash	34	3,124
Accounts receivable, net	325,125	309,609
Receivable from affiliates	17,732	15,659
Inventories	77,444	43,284
Other current assets	11,310	8,944
Total current assets	544,625	416,065
Property, plant and equipment, net	902,289	800,361
Equity method investments	426,058	415,673
Goodwill	44,971	45,274
Other intangible assets, net	19,383	20,656
Other noncurrent assets, net	23,042	18,873
Total assets	1,960,368	1,716,902
Current liabilities:
Accounts payable	264,052	234,431
Payable to affiliates	22,491	21,406
Accrued liabilities	79,309	63,126
Payables to pre-petition creditors		0
Deferred revenue	21,071	23,688
Other current liabilities	623	543
Current portion of long-term debt	44	40
Total current liabilities	387,590	343,234
Long-term debt	800,788	490,946
Deferred income taxes	47,193	49,059
Other noncurrent liabilities	$ 19,712	$ 46,769
Commitments and contingencies
Owners’ equity excluding noncontrolling interests in consolidated subsidiaries	$ 606,747	$ 716,965
Noncontrolling interests in consolidated subsidiaries	98,338	69,929
Total owners’ equity	705,085	786,894
Total liabilities and owners’ equity	1,960,368	1,716,902
Consolidation, Eliminations [Member]
Current assets:
Cash and cash equivalents	(2,257)	(4,101)	$ (3,059)	$ (1,536)
Restricted cash	0	0
Accounts receivable, net	0	0
Receivable from affiliates	(3,477)	(7,976)
Inventories	0	0
Other current assets	0	0
Total current assets	(5,734)	(12,077)
Property, plant and equipment, net	0	0
Equity method investments	(1,738,797)	(1,737,693)
Goodwill	0	0
Other intangible assets, net	0	0
Other noncurrent assets, net	0	0
Total assets	(1,744,531)	(1,749,770)
Current liabilities:
Accounts payable	0	0
Payable to affiliates	(3,477)	(7,974)
Accrued liabilities	(4)	0
Payables to pre-petition creditors		0
Deferred revenue	0	0
Other current liabilities	0	0
Current portion of long-term debt	0	0
Total current liabilities	(3,481)	(7,974)
Long-term debt	(56,449)	(58,854)
Deferred income taxes	0	0
Other noncurrent liabilities	$ 0	$ 0
Commitments and contingencies
Owners’ equity excluding noncontrolling interests in consolidated subsidiaries	$ (1,684,601)	$ (1,682,942)
Noncontrolling interests in consolidated subsidiaries	0	0
Total owners’ equity	(1,684,601)	(1,682,942)
Total liabilities and owners’ equity	$ (1,744,531)	$ (1,749,770)