Stockholders' Equity - Components of Stockholders' Equity (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Beginning Balance		$ 230,931	$ 222,746	$ 240,265	$ 221,656
Issuance of common stock under stock plans, including tax effects		$ (83)	$ (180)	$ (259)	$ 581
Repurchases of common stock, Shares		200,000	27,000	400,000	27,000
Repurchases of common stock		$ (3,918)	$ (820)	$ (8,015)	$ (820)
Stock-based compensation expense		$ 4,025	3,860	7,599	7,025
Accounting Standards Update [Extensible List]		us-gaap:AccountingStandardsUpdate201613Member
Net income (loss)		$ 6,292	5,304	(381)	1,229
Net change in marketable investments, net of tax		18	(11)	24	22
Foreign currency translation		(211)	746	(2,179)	1,952
Ending Balance		237,054	231,645	237,054	231,645
Common Stock [Member]
Beginning Balance		$ 249	$ 245	$ 247	$ 244
Beginning Balance, Shares		24,881,000	24,495,000	24,684,000	24,367,000
Issuance of common stock under stock plans, including tax effects		$ 0		$ 2	$ 1
Issuance of common stock under,stock plans including tax effects, Shares		16,000	17,000	213,000	145,000
Ending Balance		$ 249	$ 245	$ 249	$ 245
Ending Balance, Shares		24,897,000	24,512,000	24,897,000	24,512,000
Additional Paid-in Capital [Member]
Beginning Balance		$ 281,453	$ 265,691	$ 278,057	$ 261,766
Issuance of common stock under stock plans, including tax effects		(83)	(180)	(261)	580
Stock-based compensation expense		4,025	3,860	7,599	7,025
Ending Balance		285,395	269,371	285,395	269,371
Retained Earnings [Member]
Beginning Balance		171,008	170,556	177,681	174,631
Net income (loss)		6,292	5,304	(381)	1,229
Ending Balance		177,300	175,860	177,300	175,860
Treasury Stock [Member]
Beginning Balance		$ (215,246)	$ (207,067)	$ (211,149)	$ (207,067)
Beginning Balance, Shares		5,639,000	5,305,000	5,437,000	5,305,000
Repurchases of common stock, Shares		202,000	27,000	404,000	27,000
Repurchases of common stock		$ (3,918)	$ (820)	$ (8,015)	$ (820)
Ending Balance		$ (219,164)	$ (207,887)	$ (219,164)	$ (207,887)
Ending Balance, Shares		5,841,000	5,332,000	5,841,000	5,332,000
Accumulated Other Comprehensive Loss [Member]
Beginning Balance		$ (6,533)	$ (6,679)	$ (4,571)	$ (7,918)
Net change in marketable investments, net of tax		18	(11)	24	22
Foreign currency translation	[1]	(211)	746	(2,179)	1,952
Ending Balance		$ (6,726)	$ (5,944)	$ (6,726)	$ (5,944)

[1] The Company does not record tax provisions or benefits for the net changes in foreign currency translation adjustments as it intends to permanently reinvest undistributed earnings of its foreign subsidiaries.