Income Taxes - Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Deferred Tax Assets
Allowance for expected credit losses	$ 1,404	$ 1,825
Accrued paid time off	2,801	2,504
Foreign net operating loss (NOL) carry forward	229	91
State net operating loss (NOL) carry forward	502	522
Stock option compensation	1,586	1,680
Deferred rent	4,224	2,566
Deferred compensation	4,692	5,358
Foreign tax credits	7,236	6,677
Foreign exchange	4,532	4,014
Foreign deferred	875	727
Accrued bonus	5,696	5,303
Impairment	2,650
Accrued liabilities and other	6,513	6,660
Deferred Tax Assets, gross, before valuation allowance	43,324	39,008
Less: Valuation Allowance	(7,607)	(7,048)	$ (6,839)	$ (5,374)
Total Deferred Tax Assets	35,717	31,960
Deferred Tax Liabilities
Retention	(407)	(637)
Prepaid expenses	(366)	(726)
Payroll taxes	(697)	(544)
Unbilled revenue	(409)	(607)
Depreciation	(270)	(1,920)
Amortization	(99,045)	(68,194)
Deferred gain and other	(2,561)	(1,245)
Total Deferred Tax Liabilities	(103,755)	(73,873)
Total Net Deferred Tax Liability	(68,038)	(41,913)
State and Local Jurisdiction
Deferred Tax Assets
Tax credits	$ 384	$ 1,081