Derivative Instruments And Hedging Activities - Fair Value of Derivative Instruments (Detail) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Assets	$ 59	$ 88
Liabilities	1,511	1,716
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Assets	59	57
Liabilities	53	184
Designated as Hedging Instrument | Long-term debt | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Liabilities	1,448	1,530
Designated as Hedging Instrument | FX forwards | Accounts payable and accrued liabilities | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Liabilities	0	16
Designated as Hedging Instrument | Cross-currency swap | Other current assets | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Assets	2	0
Designated as Hedging Instrument | Cross-currency swap | Other assets | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Assets	26	0
Designated as Hedging Instrument | Cross-currency swap | Accounts payable and accrued liabilities | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Liabilities	7	23
Designated as Hedging Instrument | Cross-currency swap | Other liabilities | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Liabilities	32	144
Designated as Hedging Instrument | Interest Rate Swap | Other current assets | Fair Value Hedging
Derivatives, Fair Value [Line Items]
Assets	8	0
Designated as Hedging Instrument | Interest Rate Swap | Other assets | Fair Value Hedging
Derivatives, Fair Value [Line Items]
Assets	23	57
Designated as Hedging Instrument | Interest Rate Swap | Other liabilities | Fair Value Hedging
Derivatives, Fair Value [Line Items]
Liabilities	14	1
Not Designated as Accounting Hedges | FX forwards | Other current assets
Derivatives, Fair Value [Line Items]
Assets	0	31
Not Designated as Accounting Hedges | FX forwards | Accounts payable and accrued liabilities
Derivatives, Fair Value [Line Items]
Liabilities	$ 10	$ 2