Variable Interest Entities - Schedule of Variable Interest Entities (Details) - USD ($)
$ in Thousands
Sep. 30, 2016
Dec. 31, 2015
Sep. 30, 2015
Dec. 31, 2014
Variable Interest Entity [Line Items]        
Cash and cash equivalents $ 65,733 $ 94,808 $ 103,196 $ 101,656
Restricted cash 11,562 14,609    
Trade receivables 39,395 45,292    
Prepaid expenses 15,529 14,498    
Other current assets 8,445 6,929    
Total current assets 209,534 203,329    
Restricted cash 13,652 36,875    
Property, plant and equipment, net 3,182,054 3,294,620    
Finite-lived intangible assets, net 92,550 97,722    
Other assets 23,879 25,183    
Total assets 3,653,974 3,829,592    
Accounts payable and other accrued liabilities 32,868 42,776    
Accrued construction costs 1,155 23,565    
Accrued interest 3,071 9,035    
Other current liabilities 2,668 2,156    
Total current liabilities 219,921 520,687    
Other long-term liabilities 59,234 52,427    
Total liabilities 1,769,757 $ 2,053,830    
Variable Interest Entity, Primary Beneficiary [Member]        
Variable Interest Entity [Line Items]        
Cash and cash equivalents 12,433      
Restricted cash 4,289      
Trade receivables 3,953      
Prepaid expenses 3,919      
Other current assets 1,771      
Total current assets 26,365      
Restricted cash 3,202      
Property, plant and equipment, net 1,443,557      
Finite-lived intangible assets, net 2,113      
Other assets 16,155      
Total assets 1,491,392      
Accounts payable and other accrued liabilities 8,919      
Accrued construction costs 754      
Accrued interest 127      
Other current liabilities 1,481      
Total current liabilities 11,281      
Other long-term liabilities 15,675      
Total liabilities $ 26,956