Fair Value Measurements Schedule of Fair Value of assets and liabilities measured on a recurring basis (Details) - USD ($) $ / shares in Units, $ in Thousands		6 Months Ended
		Jun. 30, 2016	Dec. 31, 2015
Forward Contracts | Not Designated as Hedging Instrument | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability for Commodity Hedges, Current		$ 417	$ 1,015
Derivative liability for commodity hedges	[1]	417	1,015
Forward Contracts | Not Designated as Hedging Instrument | Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability for commodity hedges		0	0
Forward Contracts | Not Designated as Hedging Instrument | Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability for commodity hedges		417	1,015
Forward Contracts | Not Designated as Hedging Instrument | Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liability for commodity hedges		$ 0	$ 0
Convertible Notes Due in 2019 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Share Price		$ 1.64
Fair Value Assumptions, Expected Volatility Rate		71.00%
Fair Value Inputs, Entity Credit Risk		48.16%
Fair Value Assumptions, Risk Free Interest Rate		0.79%

[1] As of June 30, 2016 and December 31, 2015 the entire derivative liability for commodity hedges of $417 and $1,015, respectively, are short-term and are included in accrued and other current liabilities in the Condensed Consolidated Balance Sheets.