Derivatives and Hedging Instruments - Gain (Loss) on Derivatives Not Designated as Hedging Instruments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Derivative [Line Items]
Interest expense	$ 41	$ 91	$ 80	$ 174
(Gain) loss reclassified from AOCI	0	24	0	43
Cost of services
Derivative [Line Items]
Cost of revenue	453	413	916	828
Foreign exchange contracts | Other income (expense), net
Derivative [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	(6)	(3)	(12)	(8)
Interest rate contracts | Cost of services | Cash Flow Hedging
Derivative [Line Items]
(Gain) loss reclassified from AOCI	0	(19)	0	(34)
Interest rate contracts | Interest expense | Cash Flow Hedging
Derivative [Line Items]
(Gain) loss reclassified from AOCI	0	(5)	0	(9)
Interest rate contracts | Cost of services | Cost of services
Derivative [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	$ 0	$ 14	$ 0	$ 14