Software and Other Intangible Assets - Summary of Carrying Amount and Accumulated Amortization of Other Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 532,703	$ 536,504
Accumulated Amortization	(240,044)	(214,521)
Total	292,659	321,983
Software for resale
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	129,771	130,261
Accumulated Amortization	(127,842)	(123,418)
Total	1,929	6,843
Software for internal use
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	435,706	430,330
Accumulated Amortization	(270,699)	(240,717)
Total	165,007	189,613
Software
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	565,477	560,591
Accumulated Amortization	(398,541)	(364,135)
Total	166,936	196,456
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	508,808	512,389
Accumulated Amortization	(221,889)	(197,787)
Total	286,919	314,602
Trademarks and trade names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	23,895	24,115
Accumulated Amortization	(18,155)	(16,734)
Total	$ 5,740	$ 7,381