Derivative Instruments And Hedging Activities - Summary of Notional Amounts of Outstanding Foreign Exchange Forwards (Detail) - Not Designated as Accounting Hedges € in Millions, ¥ in Millions, £ in Millions, $ in Millions, $ in Millions, $ in Millions	Dec. 31, 2019 CAD ($)	Dec. 31, 2019 SGD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2019 EUR (€)	Dec. 31, 2019 JPY (¥)	Dec. 31, 2019 GBP (£)	Dec. 31, 2018 CAD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 EUR (€)	Dec. 31, 2018 JPY (¥)	Dec. 31, 2018 GBP (£)
Contracts to sell USD for GBP
Derivative [Line Items]
Notional Amount			$ 235			£ 178		$ 310			£ 241
Contracts to sell USD for Japanese Yen
Derivative [Line Items]
Notional Amount			29		¥ 3,200			14		¥ 1,600
Contracts to sell USD for Canadian dollars
Derivative [Line Items]
Notional Amount	$ 110		83				$ 130	99
Contracts to sell USD for Singapore dollars
Derivative [Line Items]
Notional Amount		$ 56	41
Contracts to sell USD for Euros
Derivative [Line Items]
Notional Amount			$ 421	€ 378				$ 213	€ 185
Contracts to sell Euros for GBP
Derivative [Line Items]
Notional Amount				€ 25		£ 21