Variable Interest Entities - Schedule of Assets and Liabilities related to Variable Interest Entities Securitization Transactions (Details) - USD ($) $ in Millions	Mar. 31, 2022	Mar. 31, 2021
Variable Interest Entity [Line Items]
Restricted cash	$ 2,065	$ 1,957
Net securitized assets	82,432	79,192
Other assets	2,466	2,473
Debt	109,152	109,725
Other liabilities	6,224	5,548
Other assets [Member]
Variable Interest Entity [Line Items]
Restricted cash	1,929	1,957
Net securitized assets	32,818	28,344
Other assets	66	89
Other liabilities [Member]
Variable Interest Entity [Line Items]
Debt	26,864	24,212
Other liabilities	10	14
Retail Finance Receivables [Member] | Other assets [Member]
Variable Interest Entity [Line Items]
Restricted cash	1,284	1,521
Net securitized assets	20,932	21,745
Other assets	51	46
Retail Finance Receivables [Member] | Other liabilities [Member]
Variable Interest Entity [Line Items]
Debt	18,562	19,665
Other liabilities	8	13
Investments In Operating Leases, Net [Member] | Other assets [Member]
Variable Interest Entity [Line Items]
Restricted cash	645	436
Net securitized assets	11,886	6,599
Other assets	15	43
Investments In Operating Leases, Net [Member] | Other liabilities [Member]
Variable Interest Entity [Line Items]
Debt	8,302	4,547
Other liabilities	$ 2	$ 1