Revenue - Schedule of Estimated Investment Advisory, Administration Fees Expected to be Recognized in Future, Related to Unsatisfied Portion of Performance Obligations (Detail 1) - USD ($) $ in Millions |
Mar. 31, 2022 |
Mar. 31, 2021 |
|---|---|---|
| Investment Advisory, Administration Fees and Securities Lending Revenue [Member] | ||
| Schedule of Investment Advisory Administration Fees and Performance Fees by Type [line Items] | ||
| Revenue, Remaining Performance Obligation | $ 481 | $ 516 |