Fair Value Measurements Schedule of Fair Value of assets and liabilities measured on a recurring basis (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Convertible Notes Due in 2019 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible Debt	$ 22,323	$ 22,323
Senior Secured Notes Due in 2018 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes	$ 177,019	$ 177,019