Derivatives and Hedging - Schedule of Derivative Gains (Losses) Recognized in the Consolidated Financial Statements (Details) - Foreign exchange contracts - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Derivative [Line Items]
(Loss) gain recognized in Accumulated other comprehensive loss	$ (2)	$ (2)	$ 11	$ (13)
Derivative gains (losses) reclassified from accumulated other comprehensive loss	0	(6)	(1)	(11)
Total revenue
Derivative [Line Items]
Derivative gains (losses) reclassified from accumulated other comprehensive loss	0	(5)	(1)	(9)
Compensation and benefits
Derivative [Line Items]
Derivative gains (losses) reclassified from accumulated other comprehensive loss	0	(1)	0	(1)
Interest expense
Derivative [Line Items]
Derivative gains (losses) reclassified from accumulated other comprehensive loss	$ 0	$ 0	$ 0	$ (1)