Stockholders' Equity - Components of Stockholders' Equity (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Beginning Balance		$ 231,645	$ 210,099	$ 221,656	$ 203,907
Issuance of common stock under stock plans, including tax effects		284	(499)	865	1,323
Repurchases of common stock		$ (3,262)	$ (15,100)	$ (4,082)	$ (15,112)
Repurchases of common stock, Shares		100,000	300,000	100,000	300,000
Stock-based compensation expense		$ 4,144	$ 3,905	$ 11,169	$ 11,036
Accounting Standards Update [Extensible List]		us-gaap:AccountingStandardsUpdate201613Member
Net income		$ 2,484	5,414	3,713	23,436
Net change in interest rate swap, net of tax			(5)		259
Net change in marketable investments, net of tax		30	(54)	52	(147)
Foreign currency translation		(2,435)	(4,971)	(483)	(10,813)
Ending Balance		232,890	213,889	232,890	213,889
Common Stock Member
Beginning Balance		$ 245	$ 242	$ 244	$ 241
Beginning Balance, Shares		24,512,000	24,159,000	24,367,000	24,085,000
Issuance of common stock under stock plans, including tax effects		$ 2	$ 2	$ 3	$ 3
Issuance of common stock under,stock plans including tax effects, Shares		160,000	193,000	305,000	267,000
Ending Balance		$ 247	$ 244	$ 247	$ 244
Ending Balance, Shares		24,672,000	24,352,000	24,672,000	24,352,000
Additional Paid-in Capital Member
Beginning Balance		$ 269,371	$ 254,937	$ 261,766	$ 245,985
Issuance of common stock under stock plans, including tax effects		282	(501)	862	1,320
Stock-based compensation expense		4,144	3,905	11,169	11,036
Ending Balance		273,797	258,341	273,797	258,341
Retained Earnings Member
Beginning Balance		175,860	170,847	174,631	152,825
Net income		2,484	5,414	3,713	23,436
Ending Balance		178,344	176,261	178,344	176,261
Treasury Stock Member
Beginning Balance		$ (207,887)	$ (207,067)	$ (207,067)	$ (191,955)
Beginning Balance, Shares		5,332,000	5,305,000	5,305,000	5,027,000
Repurchases of common stock		$ (3,262)		$ (4,082)	$ (15,112)
Repurchases of common stock, Shares		105,000		132,000	278,000
Ending Balance		$ (211,149)	$ (207,067)	$ (211,149)	$ (207,067)
Ending Balance, Shares		5,437,000	5,305,000	5,437,000	5,305,000
Accumulated Other Comprehensive Income (Loss) Member
Beginning Balance		$ (5,944)	$ (8,860)	$ (7,918)	$ (3,189)
Net change in interest rate swap, net of tax			(5)		259
Net change in marketable investments, net of tax		30	(54)	52	(147)
Foreign currency translation	[1]	(2,435)	(4,971)	(483)	(10,813)
Ending Balance		$ (8,349)	$ (13,890)	$ (8,349)	$ (13,890)

[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.