Finance Receivables, Net - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended	12 Months Ended
Sep. 30, 2024	Sep. 30, 2024	Mar. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable accrued interest before allowance for credit loss	$ 394	$ 394	$ 396
Gross Charges Off	0	0	0
Retail Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable accrued interest before allowance for credit loss	321	321	318
Gross Charges Off		435	776
Dealer Products [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable accrued interest before allowance for credit loss	$ 73	$ 73	$ 78

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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