Fair Value Measurements Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Estimated fair value of convertible debt	$ 26,594		$ 21,966
Carrying value of convertible debt	57,500		57,500
Line of Credit Facility, Fair Value of Amount Outstanding	22,100
Line of Credit Facility, Amount Outstanding	22,100		66,100
Forward Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative, Notional Amount	2,221		3,080
Gain (Losses) as a result of changes in the fair value of the contracts	(57)	$ (210)
Letters of Credit Outstanding as Collateral Associated with Commodity Hedges	$ 1,100
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	$ 2.70
Expected volatility	67.80%
Credit spreads	69.21%
Risk-free interest rate	1.05%
Senior Secured Notes Due in 2016 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes, Fair Value Disclosure	$ 5,073		160,662
Senior Notes, Carrying Value			210,000
Carrying value of senior secured notes	6,681		6,681
Senior Secured Notes Due in 2018 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes, Fair Value Disclosure	149,336
Carrying value of senior secured notes	$ 203,319		$ 203,319