Basis of Presentation, Accounting Policies and Going Concern - Senior Convertible Notes (Details) - Convertible Senior Notes Due 2019 - USD ($) $ in Thousands		12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Nov. 03, 2014	Oct. 31, 2014
Convertible Senior Notes
Senior Convertible Notes carrying value	$ 159,011	$ 159,011	$ 200,000	$ 159,011	$ 177,787	$ 200,000	$ 200,000	$ 200,000
Number of shares issued on conversion of debt	51,128,938	13,200,000	64,308,680