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]
Repurchased shares (in shares)	4,900,000
Stock repurchases	$ (30,600)
Ending balance (in shares) at Jun. 30, 2020		39,007,576			12,143,433
Ending balance at Jun. 30, 2020	49,730	$ 255,446	122	(124,105)	$ (81,733)
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)	(2,685)			(2,685)
Unrealized loss on available-for-sale securities, net of taxes	(2)		(2)
Issuance of common stock for employee stock purchase (in shares)		22,556
Issuance of stock for ESPP purchases	134	$ 134
Repurchased shares (in shares)					4,932,977
Stock repurchases	(30,642)				$ (30,642)
Exercise of stock options, net of shares withheld for employee taxes (in shares)		2,300
Exercise of stock options, net of shares withheld for employee taxes	19	$ 19
Release of restricted stock units and awards (in shares)		408,451
Release of restricted stock units and awards	0
Stock-based compensation	3,433	$ 3,433
Ending balance (in shares) at Sep. 30, 2020		39,058,091			12,143,433
Ending balance at Sep. 30, 2020	54,014	$ 256,875	122	(121,250)	$ (81,733)
Beginning balance (in shares) at Jun. 30, 2020		39,007,576			12,143,433
Beginning balance at Jun. 30, 2020	49,730	$ 255,446	122	(124,105)	$ (81,733)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	2,855			2,855
Issuance of common stock for employee stock purchase (in shares)		12,394
Issuance of stock for ESPP purchases	71	$ 71
Exercise of stock options, net of shares withheld for employee taxes (in shares)		2,300
Exercise of stock options, net of shares withheld for employee taxes	19	$ 19
Release of restricted stock units and awards (in shares)		35,821
Release of restricted stock units and awards	0
Stock-based compensation	1,339	$ 1,339
Ending balance (in shares) at Sep. 30, 2020		39,058,091			12,143,433
Ending balance at Sep. 30, 2020	54,014	$ 256,875	122	(121,250)	$ (81,733)
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)	11,148			11,148
Unrealized loss on available-for-sale securities, net of taxes	531		531
Issuance of common stock for employee stock purchase (in shares)		25,033
Issuance of stock for ESPP purchases	150	$ 150
Exercise of stock options, net of shares withheld for employee taxes (in shares)		325,737
Exercise of stock options, net of shares withheld for employee taxes	2,864	$ 2,864
Release of restricted stock units and awards (in shares)		448,772
Release of restricted stock units and awards	0
Stock Issued During Period, Value, New Issues	50,118	$ 50,118
Stock Issued During Period, Shares, New Issues		5,207,137
Stock-based compensation	1,997	$ 1,997
Ending balance (in shares) at Sep. 30, 2021		45,167,893			12,143,433
Ending balance at Sep. 30, 2021	130,789	$ 313,885	653	(102,016)	$ (81,733)
Beginning balance (in shares) at Jun. 30, 2021		43,252,670			12,143,433
Beginning balance at Jun. 30, 2021	111,726	$ 299,124	122	(105,787)	$ (81,733)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	3,771			3,771
Unrealized loss on available-for-sale securities, net of taxes			531
Issuance of common stock for employee stock purchase (in shares)		9,490
Issuance of stock for ESPP purchases	61	$ 61
Release of restricted stock units and awards (in shares)		8,407
Release of restricted stock units and awards	0
Stock Issued During Period, Value, New Issues	14,285	$ 14,285
Stock Issued During Period, Shares, New Issues		1,897,326
Stock-based compensation	415	$ 415
Ending balance (in shares) at Sep. 30, 2021		45,167,893			12,143,433
Ending balance at Sep. 30, 2021	$ 130,789	$ 313,885	$ 653	$ (102,016)	$ (81,733)