Consolidated Statements of Stockholders' Equity - 6 months ended Jun. 30, 2015 - USD ($) $ in Thousands	Total	Common Stock	Additional paid-in capital	Accumulated deficit
Balance at Dec. 31, 2014	$ 30,409	$ 41	$ 143,086	$ (112,718)
Balance (shares) at Dec. 31, 2014	40,856,815	40,856,815
Stock-based compensation expense	$ 1,044		1,044
Exercise of stock options	$ 255		255
Exercise of stock options (shares)	56,250	56,250
Net loss	$ (15,281)			(15,281)
Balance at Jun. 30, 2015	$ 16,427	$ 41	$ 144,385	$ (127,999)
Balance (shares) at Jun. 30, 2015	40,913,065	40,913,065