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, 2018		37,652,498			6,823,147
Beginning balance at Dec. 31, 2018	$ 99,660	$ 246,415	$ 116	$ (98,521)	$ (48,350)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(21,023)
Unrealized loss on available-for-sale securities, net of taxes	16		16
Issuance of common stock for employee stock purchase (in shares)		21,741
Issuance of stock for ESPP purchase	165	$ 165
Exercise of stock options, net of shares withheld for employee taxes (in shares)		173,131
Issuance of stock for ESPP purchases	1,240	$ 1,240
Release of restricted stock units and awards (in shares)		771,522
Release of restricted stock units and awards	0
Stock-based compensation	$ 4,371	$ 4,371
Ending balance (in shares) at Sep. 30, 2019	38,618,922	38,618,892			6,823,147
Ending balance at Sep. 30, 2019	$ 84,429	$ 252,191	132	(119,544)	$ (48,350)
Beginning balance (in shares) at Jun. 30, 2019		38,488,327			6,823,147
Beginning balance at Jun. 30, 2019	83,710	$ 250,079	138	(118,157)	$ (48,350)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(1,387)			(1,387)
Unrealized loss on available-for-sale securities, net of taxes	(6)		(6)
Issuance of common stock for employee stock purchase (in shares)		8,262
Issuance of stock for ESPP purchase	56	$ 56
Exercise of stock options, net of shares withheld for employee taxes (in shares)		111,333
Issuance of stock for ESPP purchases	869	$ 869
Release of restricted stock units and awards (in shares)		11,000
Release of restricted stock units and awards	0
Stock-based compensation	$ 1,187	$ 1,187
Ending balance (in shares) at Sep. 30, 2019	38,618,922	38,618,892			6,823,147
Ending balance at Sep. 30, 2019	$ 84,429	$ 252,191	132	(119,544)	$ (48,350)
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)
Repurchased shares (in shares)					4,932,977
Issuance of common stock for employee stock purchase (in shares)		22,556
Issuance of stock for ESPP purchase	134	$ 134
Stock repurchases	(30,642)				$ (30,642)
Exercise of stock options, net of shares withheld for employee taxes (in shares)		2,300
Issuance of stock for ESPP purchases	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
Unrealized loss on available-for-sale securities, net of taxes	0
Issuance of common stock for employee stock purchase (in shares)		12,394
Issuance of stock for ESPP purchase	71	$ 71
Exercise of stock options, net of shares withheld for employee taxes (in shares)		2,300
Issuance of stock for ESPP purchases	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)