Derivative Instruments - Fair Value of Derivative Instruments on the Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Total derivatives	$ 2	$ (108)
Total derivatives designated as hedging instruments
Derivatives, Fair Value [Line Items]
Total derivatives	3	(111)
Total derivatives designated as hedging instruments | Commodity contracts | Prepaid and other current assets/(Accrued liabilities)
Derivatives, Fair Value [Line Items]
Total derivatives	3	(111)
Total derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Total derivatives	(1)	3
Total derivatives not designated as hedging instruments | Commodity contracts | (Accrued liabilities)/Prepaid and other current assets
Derivatives, Fair Value [Line Items]
Total derivatives	$ (1)	$ 3