Derivative Instruments And Hedging Activities - Summary of Notional Amounts of Outstanding Forward Contracts Designated as a Net Investment Hedge (Detail) - Net Investment Hedging - Designated as Hedging Instrument € in Millions, £ in Millions, $ in Millions	Sep. 30, 2021 USD ($)	Sep. 30, 2021 EUR (€)	Sep. 30, 2021 GBP (£)	Dec. 31, 2020 USD ($)	Dec. 31, 2020 EUR (€)	Dec. 31, 2020 GBP (£)
Contract to sell EUR for USD
Derivative [Line Items]
Notional Amount	$ 0	€ 0		$ 627	€ 524
Contract to sell GBP for EUR
Derivative [Line Items]
Notional Amount		€ 0	£ 0		€ 148	£ 134