Subsequent Events (Details) - USD ($) $ in Thousands	2 Months Ended	12 Months Ended		32 Months Ended	38 Months Ended
	Feb. 28, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2016
Subsequent events
Remaining outstanding balance		$ 4,165	$ 7,085	$ 7,085	$ 4,165
7.50% Convertible Senior Secured Notes due 2019
Subsequent events
Principal amount of the Notes converted		$ 3,962	$ 27,500	81,463	$ 85,400
Shares of common stock issued in conversion of Notes and accrued interest thereon		700,000	5,200,000		16,120,128
Remaining outstanding balance		$ 4,165	$ 7,085	$ 7,085	$ 4,165
Subsequent Event | 7.50% Convertible Senior Secured Notes due 2019
Subsequent events
Principal amount of the Notes converted	$ 1,000
Shares of common stock issued in conversion of Notes and accrued interest thereon	200,000
Remaining outstanding balance	$ 3,600