Financial Instruments, Hedging Activities and Fair Value Measurements (Assets and Liabilities Reported at Fair Value on a Recurring Basis) (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Level 1 | Short-term Investments | Marketable Equity Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets reported at fair value on a recurring basis	$ 6	$ 5
Level 1 | Investments | Marketable Equity Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets reported at fair value on a recurring basis	97	80
Level 2 | Other Assets | Cross Currency Swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets reported at fair value on a recurring basis	13	52
Liabilities reported at fair value on a recurring basis	8
Level 2 | Other Assets | Interest Rate Swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets reported at fair value on a recurring basis	67	35
Level 2 | Accounts Payable and Accrued Liabilities | Foreign Currency Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities reported at fair value on a recurring basis	6	20
Level 2 | Other Liabilities | Cross Currency Swaps
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities reported at fair value on a recurring basis	13	4
Not Designated as Hedging Instrument [Member] | Level 2 | Other Current Assets | Foreign Currency Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets reported at fair value on a recurring basis	8	14
Not Designated as Hedging Instrument [Member] | Level 2 | Accounts Payable and Accrued Liabilities | Foreign Currency Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities reported at fair value on a recurring basis	$ 0	$ 1