Variable Interest Entities (Details) - USD ($) $ in Millions	Mar. 31, 2024	Mar. 31, 2023
Variable Interest Entity [Line Items]
VIE consolidated assets	$ 67,443	$ 62,320
Unconsolidated VIE maximum exposure to loss	1,500	1,400
Consolidated Variable Interest Entities
Variable Interest Entity [Line Items]
VIE consolidated assets	601	621
VIE consolidated liabilities	$ 41	$ 53