Consolidated Statements of Changes in Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment [Member]	Common Stock [Member] Class A Common Stock [Member]	Common Stock [Member] Class B Common Stock [Member]	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Accumulated Deficit [Member]	Accumulated Deficit [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning balance at Dec. 31, 2020	$ 378,586		$ 4	$ 3	$ 474,669		$ (93,293)		$ (2,797)
Beginning balance (in shares) at Dec. 31, 2020			44,216	30,111
Net income	14,360						14,360
Exercise of stock options	271				271
Exercise of stock options (in shares)			490
Vesting of restricted stock (in shares)			278
Conversion from Class B to Class A common stock			510	(510)
Stock-based compensation	9,644				9,644
Foreign currency translation, net of tax	(3,975)								(3,975)
Retirement related benefit plans, net of tax	143								143
Ending balance at Mar. 31, 2021	399,029		$ 4	$ 3	484,584		(78,933)		(6,629)
Ending balance (in shares) at Mar. 31, 2021			45,494	29,601
Beginning balance at Dec. 31, 2021	613,197	$ (26,070)	$ 5	$ 3	724,226	$ (50,009)	(102,087)	$ 23,939	(8,950)
Beginning balance (in shares) at Dec. 31, 2021			51,524	27,745
Net income	11,528						11,528
Issuance of common stock for employee stock purchase program	4,187				4,187
Issuance of common stock for employee stock purchase program (in shares)			77
Exercise of stock options	238				238
Exercise of stock options (in shares)			86
Vesting of restricted stock (in shares)			324
Stock-based compensation	19,403				19,403
Foreign currency translation, net of tax	(4,163)								(4,163)
Retirement related benefit plans, net of tax	105								105
Ending balance at Mar. 31, 2022	$ 618,425		$ 5	$ 3	$ 698,045		$ (66,620)		$ (13,008)
Ending balance (in shares) at Mar. 31, 2022			52,011	27,745