Consolidated Statements of Stockholders' Equity (Deficit) (unaudited) - 3 months ended Mar. 31, 2017 - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Balance at December 31, 2016 at Dec. 31, 2016	$ 42,352	$ 27	$ 132,246	$ (89,618)	$ (303)
Balance at December 31, 2016, shares at Dec. 31, 2016		27,150,674
Stock-based compensation	968		968
Exercise of stock options	$ 12		12
Exercise of stock options, shares	1,321	1,321
Issuance of shares under employee stock purchase plan	$ 854		854
Issuance of shares under employee stock purchase plan, shares		83,790
Other comprehensive income	41				41
Net loss	(6,202)			(6,202)
Balance at March 31, 2017 at Mar. 31, 2017	$ 38,025	$ 27	$ 134,080	$ (95,820)	$ (262)
Balance at March 31, 2017, shares at Mar. 31, 2017		27,235,785