Variable Interest Entities - Schedule of Assets and Liabilities related to Variable Interest Entities Securitization Transactions (Details) - USD ($) $ in Millions	Sep. 30, 2022	Mar. 31, 2022
Variable Interest Entity [Line Items]
Restricted cash	$ 1,855	$ 2,065
Net securitized assets	86,890	82,432
Other assets	2,794	2,466
Debt	108,873	109,152
Other liabilities	5,861	6,224
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Restricted cash	1,855	1,929
Net securitized assets	24,529	20,932
Other assets	77	66
Debt	29,947	26,864
Other liabilities	23	10
Variable Interest Entity, Primary Beneficiary | Other assets [Member]
Variable Interest Entity [Line Items]
Net securitized assets	36,756	32,818
Other assets	77	66
Variable Interest Entity, Primary Beneficiary | Other liabilities [Member]
Variable Interest Entity [Line Items]
Debt	29,947	26,864
Other liabilities	23	10
Retail Finance Receivables [Member] | Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Restricted cash	1,248	1,284
Retail Finance Receivables [Member] | Variable Interest Entity, Primary Beneficiary | Other assets [Member]
Variable Interest Entity [Line Items]
Net securitized assets	24,529	20,932
Other assets	63	51
Retail Finance Receivables [Member] | Variable Interest Entity, Primary Beneficiary | Other liabilities [Member]
Variable Interest Entity [Line Items]
Debt	21,316	18,562
Other liabilities	17	8
Investments In Operating Leases, Net [Member] | Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Restricted cash	607	645
Investments In Operating Leases, Net [Member] | Variable Interest Entity, Primary Beneficiary | Other assets [Member]
Variable Interest Entity [Line Items]
Net securitized assets	12,227	11,886
Other assets	14	15
Investments In Operating Leases, Net [Member] | Variable Interest Entity, Primary Beneficiary | Other liabilities [Member]
Variable Interest Entity [Line Items]
Debt	8,631	8,302
Other liabilities	$ 6	$ 2