Condensed Consolidating Financial Information - Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 264,093	$ 254,530	$ 501,149	$ 389,915
Short-term investments	31,109	20,059
Assets held for sale	76,668	75,678
Accounts receivable, net	508,355	784,671
Inventory	103,595	153,824
Other current assets	172,019	187,135
Total current assets	1,155,839	1,475,897
Property, plant and equipment, net	6,267,583	7,027,802	8,599,125
Goodwill	166,917	166,659	173,928
Investment in unconsolidated affiliates	893	415,177
Other long-term assets	595,783	452,305
Total assets	8,187,015	9,537,840
Current liabilities:
Current portion of debt	297	6,508
Trade accounts payable	264,578	271,984
Accrued liabilities	543,248	686,613
Income taxes payable	13,811	41,394
Total current liabilities	821,934	1,006,499
Long-term debt	3,578,335	3,655,200
Other long-term liabilities	522,456	552,947
Deferred income taxes	9,495	29,326
Total liabilities	4,932,220	5,243,972
Shareholders' equity	3,247,025	4,282,710
Noncontrolling interest	7,770	11,158
Total equity	3,254,795	4,293,868	4,918,789	5,981,177
Total liabilities and equity	8,187,015	9,537,840
Reportable Legal Entities | Parent Company
Current assets:
Cash and cash equivalents	1,148	873	1,170	730
Other current assets	50	50
Total current assets	1,198	923
Intercompany receivables	142,448	139,366
Investment in consolidated affiliates	3,170,254	4,183,362
Total assets	3,313,900	4,323,651
Current liabilities:
Trade accounts payable	205	71
Accrued liabilities	20,669	370
Total current liabilities	20,874	441
Intercompany payable	46,000	40,500
Total liabilities	66,874	40,941
Shareholders' equity	3,247,026	4,282,710
Total equity	3,247,026	4,282,710
Total liabilities and equity	3,313,900	4,323,651
Reportable Legal Entities | Guarantor Subsidiaries
Current assets:
Cash and cash equivalents	10,177	10	7	7,029
Other current assets	22,209	9,016
Total current assets	32,386	9,026
Intercompany receivables		11,000
Investment in consolidated affiliates	4,830,572	4,973,327
Deferred tax assets	443,049	366,818
Other long-term assets	344	12,907
Total assets	5,306,351	5,373,078
Current liabilities:
Trade accounts payable	8	3
Accrued liabilities	65,246	64,550
Total current liabilities	65,254	64,553
Long-term debt	3,796,550	3,723,138
Other long-term liabilities	22,659	35,086
Intercompany payable	1,439,390	1,370,176
Total liabilities	5,323,853	5,192,953
Shareholders' equity	(17,502)	180,125
Total equity	(17,502)	180,125
Total liabilities and equity	5,306,351	5,373,078
Reportable Legal Entities | Other Subsidiaries (Non-Guarantors)
Current assets:
Cash and cash equivalents	252,768	253,647	$ 499,972	$ 382,156
Short-term investments	31,109	20,059
Assets held for sale	76,668	75,678
Accounts receivable, net	508,355	784,671
Inventory	103,595	153,824
Other current assets	149,760	178,069
Total current assets	1,122,255	1,465,948
Property, plant and equipment, net	6,267,583	7,027,802
Goodwill	166,917	166,659
Intercompany receivables	1,342,942	1,260,310
Investment in consolidated affiliates	1,083,948	1,284,225
Investment in unconsolidated affiliates	893	415,177
Other long-term assets	813,655	507,336
Total assets	10,798,193	12,127,457
Current liabilities:
Current portion of debt	297	6,508
Trade accounts payable	264,365	271,910
Accrued liabilities	457,333	621,693
Income taxes payable	13,811	41,394
Total current liabilities	735,806	941,505
Other long-term liabilities	499,797	517,861
Deferred income taxes	452,544	396,144
Total liabilities	1,688,147	1,855,510
Shareholders' equity	9,102,276	10,260,789
Noncontrolling interest	7,770	11,158
Total equity	9,110,046	10,271,947
Total liabilities and equity	10,798,193	12,127,457
Consolidating Adjustments
Current assets:
Intercompany receivables	(1,485,390)	(1,410,676)
Investment in consolidated affiliates	(9,084,774)	(10,440,914)
Deferred tax assets	(443,049)	(366,818)
Other long-term assets	(218,216)	(67,938)
Total assets	(11,231,429)	(12,286,346)
Current liabilities:
Long-term debt	(218,215)	(67,938)
Deferred income taxes	(443,049)	(366,818)
Intercompany payable	(1,485,390)	(1,410,676)
Total liabilities	(2,146,654)	(1,845,432)
Shareholders' equity	(9,084,775)	(10,440,914)
Total equity	(9,084,775)	(10,440,914)
Total liabilities and equity	$ (11,231,429)	$ (12,286,346)