Derivatives - Schedule of Derivatives Fair Value Amounts (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Prepaid Expenses and Other Current Assets
Derivative Instruments, Gain (Loss) [Line Items]
Cash collateral	$ 2,700	$ 20,900
Other Noncurrent Assets
Derivative Instruments, Gain (Loss) [Line Items]
Cash collateral	7,000	7,000
Commodity Contract | Prepaid Expenses and Other Current Assets
Derivative Instruments, Gain (Loss) [Line Items]
Asset (Liability)	0	4,577
Commodity Contract | Other Noncurrent Assets
Derivative Instruments, Gain (Loss) [Line Items]
Asset (Liability)	2,748	0
Commodity Contract | Other Accrued Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Asset (Liability)	(595)	(9,534)
Commodity Contract | Other Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Asset (Liability)	0	(4,925)
Interest Rate Contract | Other Noncurrent Assets
Derivative Instruments, Gain (Loss) [Line Items]
Asset (Liability)	161	0
Interest Rate Contract | Other Accrued Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Asset (Liability)	3,377	0
Interest Rate Contract | Other Liabilities
Derivative Instruments, Gain (Loss) [Line Items]
Asset (Liability)	(94)	0
Over the Counter | Embedded Derivative
Derivative Instruments, Gain (Loss) [Line Items]
Asset (Liability)	$ (20,000)	$ 9,810