Consolidated Statements of Stockholders' Equity (Unaudited) - 3 months ended Mar. 31, 2016 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]
Balance at Dec. 31, 2015	$ 177,277	$ 100	$ (73)	$ 363,280	$ (182,864)	$ (3,166)
Balance, Shares at Dec. 31, 2015		100,180	(31)
Stock-based compensation	1,428			1,428
Issuance of common stock, net of issuance costs	31,391	$ 9		31,382
Issuance of common stock, net of issuance costs, Shares		9,138
Exercise of stock options and restricted stock units	8			8
Exercise of stock options and restricted stock units, Shares		140
Return of common stock to pay withholding taxes on restricted stock	(130)		$ (130)
Return of common stock to pay withholding taxes on restricted stock, Shares			(41)
Other comprehensive gain	3,796					3,796
Net loss	(12,913)				(12,913)
Balance at Mar. 31, 2016	$ 200,857	$ 109	$ (203)	$ 396,098	$ (195,777)	$ 630
Balance, Shares at Mar. 31, 2016		109,458	(72)