Derivative Instruments and Hedging Activities - Classification and Fair Value Amounts of Derivative Instruments (Detail) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	$ 27	$ 25
Derivative liability, fair value	96	6
Derivative instruments designated as hedges
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	27	23
Derivative liability, fair value	96	4
Derivative instruments designated as hedges | Interest rate contracts | Other non-current assets
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	1	0
Derivative instruments designated as hedges | Interest rate contracts | Other non-current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	95	3
Derivative instruments designated as hedges | Foreign exchange contracts | Other non-current assets
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	2	1
Derivative instruments designated as hedges | Foreign exchange contracts | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	24	22
Derivative instruments designated as hedges | Foreign exchange contracts | Other non-current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	0	0
Derivative instruments designated as hedges | Foreign exchange contracts | Accounts payable and accrued liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	1	1
Undesignated derivative instruments | Foreign exchange contracts | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	0	2
Undesignated derivative instruments | Foreign exchange contracts | Accounts payable and accrued liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	$ 0	$ 2