Convertible Senior Secured Notes (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended		44 Months Ended
	Jun. 30, 2017	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Details of Notes reflected in balance sheet
Remaining outstanding balance	$ 1,472	$ 1,472		$ 4,165
Loss on extinguishment of debt	103	204	$ 382
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		(3,000)	(2,000)	(85,425)
Conversion of debt to equity - accretion of debt discount and deferred financing costs		257		25,767
Accretion of debt discount and deferred financing costs		50		5,429
Remaining outstanding balance	$ 1,472	$ 1,472		$ 4,165
Shares of common stock issued in conversion of Notes		600,000
Shares of common stock issued in settlement of the interest make-whole provision		2,000
Loss on extinguishment of debt		$ 200	$ 400