Intangible Assets and Goodwill - Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Intangibles
Gross Carrying Amount	$ 704,223		$ 704,223		$ 702,348
Accumulated Amortization	(555,859)		(555,859)		(537,428)
Intangible Asset, net	148,364		148,364		164,920
Carrying amount of indefinite-lived trade names which are not amortizable	5,300		5,300
Aggregated amortization expense	9,900	$ 10,000	19,000	$ 21,000
Customer relationships
Intangibles
Gross Carrying Amount	507,679		507,679		507,930
Accumulated Amortization	(393,065)		(393,065)		(380,580)
Intangible Asset, net	114,614		114,614		127,350
Developed technology
Intangibles
Gross Carrying Amount	88,553		88,553		88,554
Accumulated Amortization	(88,382)		(88,382)		(88,085)
Intangible Asset, net	171		171		469
Patent
Intangibles
Gross Carrying Amount					15
Accumulated Amortization					(14)
Intangible Asset, net					1
Trade names
Intangibles
Gross Carrying Amount	5,300		5,300		5,300
Intangible Asset, net	5,300		5,300		5,300
Accumulated impairment losses	44,100		44,100		44,100
Outsource contract costs
Intangibles
Gross Carrying Amount	18,272		18,272		17,734
Accumulated Amortization	(16,813)		(16,813)		(16,334)
Intangible Asset, net	1,459		1,459		1,400
Internally developed software
Intangibles
Gross Carrying Amount	57,670		57,670		56,066
Accumulated Amortization	(47,791)		(47,791)		(43,499)
Intangible Asset, net	9,879		9,879		12,567
Purchased software
Intangibles
Gross Carrying Amount	26,749		26,749		26,749
Accumulated Amortization	(9,808)		(9,808)		(8,916)
Intangible Asset, net	$ 16,941		$ 16,941		$ 17,833