Derivative Instruments And Hedging Activities - Gains (Losses) Recognized in AOCI and Reclassified from AOCI on Derivatives (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	$ (36)	$ 0
Total, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	53	23
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	(1)	0
Total, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	(1)	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	16	8
Net Investment Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Net Investment Hedging Relationships, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	89	23
Net Investment Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	0	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	16	8
Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	(36)	0
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	(1)	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	0	0
Cross-currency swap | Net Investment Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Net Investment Hedging Relationships, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	66	15
Net Investment Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	0	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	16	8
Long-term debt | Net Investment Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Net Investment Hedging Relationships, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	23	8
Net Investment Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	0	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	0	0
Interest rate contract | Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Recognized in AOCI on Derivative, net of Tax	(36)	0
Cash Flow Hedging Relationships, Amount of Gain/(Loss) Reclassified from AOCI into Income, net of Tax	(1)	0
Gain/(Loss) Recognized in Income on Derivative (Amount Excluded from Effectiveness Testing)	$ 0	$ 0