Derivatives - Schedule of Pretax Effects of Derivative Financial Instruments Designated or Previously Designated as Effective Hedges (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Recognized in OCI (effective portion)	$ (11)	$ (22)	$ 28	$ 34
Reclassified from AOCL to Income	(7)	0	(11)	(1)
Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Recognized in OCI (effective portion)	0	0	0	0
Reclassified from AOCL to Income	(1)	(1)	(3)	(3)
Foreign currency contracts
Derivative Instruments, Gain (Loss) [Line Items]
Recognized in OCI (effective portion)	(3)	(5)	0	30
Reclassified from AOCL to Income	(6)	1	(8)	2
Cross-currency swaps
Derivative Instruments, Gain (Loss) [Line Items]
Recognized in OCI (effective portion)	(8)	(17)	28	4
Reclassified from AOCL to Income	$ 0	$ 0	$ 0	$ 0