Derivative Instruments And Hedging Activities - Schedule of Notional Amount of Net Investment Hedges (Detail) - Designated as Hedging Instrument - Cross currency swaps - EUR (€)	Dec. 31, 2020	Mar. 31, 2020
Net Investment Hedging
Derivative [Line Items]
Notional Amount		€ 2,038,000,000
2021
Derivative [Line Items]
Notional Amount	€ 265,000,000
2022
Derivative [Line Items]
Notional Amount	438,000,000
2023
Derivative [Line Items]
Notional Amount	442,000,000
2024
Derivative [Line Items]
Notional Amount	€ 443,000,000
2026
Derivative [Line Items]
Notional Amount		€ 450,000,000