Components of Working Capital - Accrued Liabilities Table (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accrued Liabilities [Line Items]
Accrued interest expense	$ 26,194	$ 24,741
Short-term asset retirement obligations	3,555	1,224
Short-term remediation and reclamation obligations	1,136	475
Income taxes payable	770	207
Total accrued liabilities	116,895	170,864	[1]
Accrued Capital Expenditures [Member]
Accrued Liabilities [Line Items]
Other accrued liabilities	60,702	128,856
Accrued Plant Purchases [Member]
Accrued Liabilities [Line Items]
Other accrued liabilities	16,425	14,023
Other Accrued Liabilities [Member]
Accrued Liabilities [Line Items]
Other accrued liabilities	$ 8,113	$ 1,338

[1] Financial information has been recast to include the financial position and results attributable to the DBJV system. See Note 1 and Note 2.