Employee Benefit Plans - Funded Status (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Change in Benefit Obligation:
Benefit obligation at beginning of period	$ 122,011	$ 100,961
Service cost	68	69
Interest cost	$ 1,686	1,984
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Selling, General and Administrative Expense.
Actuarial loss	$ (2,296)	18,861
Plan amendments	(28)	(10)
Plan curtailment	98
Benefits paid	(2,497)	(4,745)
Foreign-exchange rate changes	(1,570)	4,891
Benefit obligation at end of year	117,472	122,011
Change in Plan Assets:
Fair value of plan assets at beginning of period	87,215	75,875
Actual return on plan assets	2,950	10,755
Employer contributions	3,189	2,052
Plan participants' contributions	16
Benefits paid	(2,393)	(4,651)
Foreign-exchange rate changes	(1,005)	3,184
Fair value of plan assets at end of period	89,972	87,215
Funded status at end of year	(27,500)	(34,796)
Net amount recognized in the Consolidated Balance Sheets:
Pension liability (a)	(28,383)	(35,515)
Minimum regulatory benefit for Philippine legal entity	700	600
Amounts recognized in accumulated other comprehensive loss, net of tax consist of:
Net actuarial loss	(10,946)	(17,064)
Net amount recognized in accumulated other comprehensive loss	10,946	17,064
Plans with underfunded or non-funded accumulated benefit obligation:
Aggregate fair value of plan assets	89,972	87,215
Defined Benefit Plan, Overfunded Plan [Member]
Change in Plan Assets:
Fair value of plan assets at end of period	89,972
Plans with underfunded or non-funded accumulated benefit obligation:
Aggregate fair value of plan assets	89,972
Defined Benefit Plan, Underfunded Plan [Member]
Change in Plan Assets:
Fair value of plan assets at beginning of period	87,215
Fair value of plan assets at end of period		87,215
Plans with underfunded or non-funded accumulated benefit obligation:
Aggregate fair value of plan assets		87,215
Underfunded Or Unfunded Plan [Member]
Change in Plan Assets:
Fair value of plan assets at beginning of period	87,215
Fair value of plan assets at end of period	89,972	87,215
Plans with underfunded or non-funded accumulated benefit obligation:
Aggregate projected benefit obligation	117,472	122,010
Aggregate accumulated benefit obligation	117,472	122,010
Aggregate fair value of plan assets	89,972	87,215
U.K. And Asterion Plans
Net amount recognized in the Consolidated Balance Sheets:
Pension liability (a)	(28,383)	(35,515)
U.K. Pension Plan
Net amount recognized in the Consolidated Balance Sheets:
Pension liability (a)	(23,000)	(29,700)
Asterion Pension Plan
Net amount recognized in the Consolidated Balance Sheets:
Pension liability (a)	(2,500)	(2,700)
Norway Pension Plan
Net amount recognized in the Consolidated Balance Sheets:
Pension liability (a)	(100)	(100)
German Pension Plan
Net amount recognized in the Consolidated Balance Sheets:
Pension liability (a)	(2,100)	$ (2,400)
German Pension Plan | Unfunded Plan
Change in Plan Assets:
Fair value of plan assets at end of period	0
Plans with underfunded or non-funded accumulated benefit obligation:
Aggregate fair value of plan assets	$ 0