Derivative Instruments And Hedging Activities - Summary of Net Gain (Loss) on Interest Rate Swaps Designated in Fair Value Hedge (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense, net	$ (208)	$ (215)	$ (209)
Designated as Hedging Instrument | Interest Rate Swap | Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Fair value changes on interest rate swaps	25	2	(9)
Fair value changes on hedged debt	(25)	(2)	9
Designated as Hedging Instrument | Interest Rate Swap | Interest Expense | Fair Value hedge Net Interest Settlements and Accruals
Derivative Instruments, Gain (Loss) [Line Items]
Net interest settlements and accruals on interest rate swaps	$ 3	$ (2)	$ 7