Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Difference between income tax provision computed at the statutory Federal income tax rate and financial statement income tax
Provision at Federal rate of 21%									$ 17,925	$ 22,202	$ 18,267
State income taxes, net of Federal impact									3,430	2,792	2,985
Research and experimentation credits									(2,705)	(3,314)	(4,040)
Stock award vesting									(540)	(3,661)	(1,513)
Tax uncertainties									(403)	(56)	(122)
Section 199 manufacturing deduction											168
Section 162(m) compensation limitation									4,494	978	951
Foreign rate differential									462	930	1,238
Valuation allowance for deferred tax assets									1,002	(495)	(177)
Withholding Tax									2,572	2,408	2,070
Other impact of foreign operations									621	227	685
Statutory rate change									71	(10)	(87)
Other									(284)	952	432
Total income tax provision	$ 6,423	$ 9,176	$ 3,884	$ 7,162	$ 1,633	$ 7,262	$ 7,458	$ 6,600	$ 26,645	$ 22,953	$ 20,857