Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive income (loss)
Beginning Balance at Dec. 31, 2018	$ 310,424	$ 22	$ 249,194	$ 60,484	$ 724
Beginning Balance, shares at Dec. 31, 2018		21,778,632
Stock-based compensation	3,586		3,586
Employee stock purchases	1,525		1,525
Employee stock purchases, shares		16,767
Restricted stock awards issued, net of forfeitures, shares		66,944
Vesting of restricted stock units	(59)		(59)
Vesting of restricted stock units, shares		11,265
Shares withheld related to net restricted stock settlement	(655)		(655)
Shares withheld related to net restricted stock settlement, shares		(12,045)
Stock options exercised	1,635		1,635
Stock options exercised, shares		69,779
Net income (loss)	5,302			5,302
Other comprehensive income	136				136
Ending Balance at Mar. 31, 2019	321,894	$ 22	255,226	65,786	860
Ending Balance, shares at Mar. 31, 2019		21,931,342
Beginning Balance at Dec. 31, 2019	344,621	$ 22	263,252	81,434	(87)
Beginning Balance, shares at Dec. 31, 2019		22,031,410
Stock-based compensation	2,784		2,784
Employee stock purchases	1,088		1,088
Employee stock purchases, shares		27,954
Restricted stock awards issued, net of forfeitures, shares		(27,729)
Vesting of restricted stock units	(7)		(7)
Vesting of restricted stock units, shares		10,167
Shares withheld related to net restricted stock settlement	(166)		(166)
Shares withheld related to net restricted stock settlement, shares		(3,609)
Stock options exercised	$ 60		60
Stock options exercised, shares	6,334	6,334
Net income (loss)	$ (1,589)			(1,589)
Other comprehensive income	509				509
Ending Balance at Mar. 31, 2020	$ 347,300	$ 22	$ 267,011	$ 79,845	$ 422
Ending Balance, shares at Mar. 31, 2020		22,044,527