Fair Value Measurements Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes, Fair Value Disclosure	$ 179,846		$ 179,846
Carrying value of senior secured notes	210,000		210,000		$ 210,000
Estimated fair value of convertible debt	43,615		43,615
Carrying value of convertible debt	57,500		57,500		57,500
Line of Credit Facility, Fair Value of Amount Outstanding	68,300		68,300
Line of Credit Facility, Amount Outstanding	68,300		68,300		$ 59,200
Letters of Credit Outstanding as Collateral Associated with Commodity Hedges	2,000		2,000
Forward Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, Notional Amount	4,182		4,182
Gain (Losses) as a result of changes in the fair value of the contracts	$ (252)	$ 143	$ (706)	$ 74
Convertible Notes due December 15, 2017 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stock price at the end of the period	$ 2.22		$ 2.22
Expected volatility			49.80%
Credit spreads			21.65%
Risk-free interest rate			0.81%