Consolidated Statements of Stockholders' Equity (unaudited) - 3 months ended Mar. 31, 2018 - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Balance at Dec. 31, 2017	$ 55,991	$ 28	$ 164,995	$ (109,252)	$ 220
Balance, shares at Dec. 31, 2017		28,330,460
Cumulative effect of adoption of ASU 2014-09, net of taxes	9,097			9,097
Stock-based compensation	6,694		6,694
Vesting of restricted stock units		222,624
Restricted stock units withheld to settle employee tax withholding liability	(1,022)		(1,022)
Restricted stock units withheld to settle employee tax withholding liability, shares		(27,771)
Exercise of stock options	$ 1,466	$ 1	1,465
Exercise of stock options, shares	153,744	153,744
Issuance of shares under employee stock purchase plan	$ 881		881
Issuance of shares under employee stock purchase plan, shares		44,193
Other comprehensive income	(267)				(267)
Net loss	(12,342)			(12,342)
Balance at Mar. 31, 2018	$ 60,498	$ 29	$ 173,013	$ (112,497)	$ (47)
Balance, shares at Mar. 31, 2018		28,723,250