Convertible Senior Secured Notes (Details) - USD ($) $ in Thousands, shares in Millions	3 Months Ended	9 Months Ended		32 Months Ended
	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Details of Notes reflected in balance sheet
Accretion of debt discount and deferred financing costs		$ 512	$ 646
Remaining outstanding balance		5,772		$ 7,085
Loss on extinguishment of debt	$ 25	382	2,400
7.50% Convertible Senior Secured Notes due 2019
Details of Notes reflected in balance sheet
Gross proceeds				90,000
Initial value of interest make-whole derivative reported as debt discount				(9,270)
Conversion option reported as debt discount and APIC				(22,336)
Conversion of debt to equity - principal		(1,962)	(26,300)	(81,463)
Conversion of debt to equity - accretion of debt discount and deferred financing costs		424		25,003
Accretion of debt discount and deferred financing costs		225		5,151
Remaining outstanding balance		$ 5,772		$ 7,085
Shares of common stock issued in conversion of Notes		0.4
Loss on extinguishment of debt		$ 400	$ 2,400