Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock Outstanding [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Total
Balances (in shares) at Dec. 31, 2017	32,112		7,688
Balances at Dec. 31, 2017	$ 5	$ 297,950	$ (71,793)	$ (27,089)	$ (705)	$ 198,368
Cumulative-effect adjustment from adoption of ASU 2014-09 at Dec. 31, 2017				4,353		4,353
Issuance of common stock in connection with employee stock purchase plan (in shares)	201
Issuance of common stock in connection with employee stock purchase plan		1,831				$ 1,831
Issuance of common stock in connection with exercise of options (in shares)	81					81
Issuance of common stock in connection with exercise of options		560				$ 560
Vesting of restricted stock units (in shares)	425
Vesting of restricted stock units
Purchases of treasury stock in connection with tax withholdings on restricted stock grants (in shares)			170
Purchases of treasury stock in connection with tax withholdings on restricted stock grants			$ (2,101)			(2,101)
Repurchases of common stock (in shares)	(437)		437
Repurchases of common stock			$ (5,248)			(5,248)
Stock-based compensation expense		10,319				10,319
Comprehensive income (loss)				(7,716)	(571)	(8,287)
Balances (in shares) at Dec. 31, 2018	32,382		8,295
Balances at Dec. 31, 2018	$ 5	310,660	$ (79,142)	(30,452)	(1,276)	199,795
Issuance of common stock in connection with employee stock purchase plan (in shares)	172
Issuance of common stock in connection with employee stock purchase plan		1,534				$ 1,534
Issuance of common stock in connection with exercise of options (in shares)	230					238
Issuance of common stock in connection with exercise of options		1,289				$ 1,289
Vesting of restricted stock units (in shares)	504
Vesting of restricted stock units
Repurchases of common stock (in shares)	(785)		785
Repurchases of common stock			$ (9,767)			(9,767)
Stock-based compensation expense		11,714				11,714
Comprehensive income (loss)				(5,418)	(204)	(5,622)
Purchases of treasury stock in connection with tax withholdings on restricted stock grants and exercise of options (in shares)			214
Purchases of treasury stock in connection with tax withholdings on restricted stock grants and exercise of options			$ (2,786)			(2,786)
Balances (in shares) at Dec. 31, 2019	32,503		9,294
Balances at Dec. 31, 2019	$ 5	$ 325,197	$ (91,695)	$ (35,870)	$ (1,480)	$ 196,157