CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS EQUITY - USD ($) $ in Thousands	Total	Common Stock and Additional Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit	Treasury Stock
Beginning balance (in shares) at Dec. 31, 2019		38,624,784			7,210,456
Beginning balance at Dec. 31, 2019	$ 83,757	$ 253,289	$ 124	$ (118,565)	$ (51,091)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(4,828)			(4,828)
Unrealized gain on available-for-sale securities, net of taxes	(2)		(2)
Issuance of common stock for employee stock purchase (in shares)		10,162
Issuance of stock for ESPP purchases	$ 63	$ 63
Repurchased shares (in shares)	2,000,000.0				2,012,766
Repurchase of stock	$ (11,975)				$ (11,975)
Release of restricted stock units and awards (in shares)		189,735
Release of restricted stock units and awards	0
Stock-based compensation	729	$ 729
Ending balance (in shares) at Mar. 31, 2020		38,824,681			9,223,222
Ending balance at Mar. 31, 2020	67,744	$ 254,081	122	(123,393)	$ (63,066)
Beginning balance (in shares) at Dec. 31, 2020		39,161,214			12,143,433
Beginning balance at Dec. 31, 2020	63,981	$ 258,756	122	(113,164)	$ (81,733)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	2,036			2,036
Unrealized gain on available-for-sale securities, net of taxes	0
Issuance of common stock for employee stock purchase (in shares)		15,543
Issuance of stock for ESPP purchases	89	$ 89
Exercise of stock options, net of shares withheld for employee taxes (in shares)		306,987
Issuance of stock for ESPP purchases	2,724	$ 2,724
Release of restricted stock units and awards (in shares)		227,055
Release of restricted stock units and awards	0
Stock Issued During Period, Value, New Issues	35,937	$ 35,937
Stock Issued During Period, Shares, New Issues		3,309,811
Stock-based compensation	531	$ 531
Ending balance (in shares) at Mar. 31, 2021		43,020,610			12,143,433
Ending balance at Mar. 31, 2021	$ 105,298	$ 298,037	$ 122	$ (111,128)	$ (81,733)