Finance Receivables, Net - Net Financing Receivables (Details) - USD ($) $ in Millions	Sep. 30, 2022	Mar. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross finance receivables	$ 88,256	$ 83,678
Allowance for credit losses	(1,366)	(1,246)
Finance receivables, net	86,890	82,432
Finance Receivables, Net [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross finance receivables	87,983	83,450
Deferred origination costs	1,358	1,330
Deferred income	(1,085)	(1,102)
Allowance for credit losses	(1,366)	(1,246)
Finance receivables, net	86,890	82,432
Finance Receivables, Net [Member] | Retail receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross finance receivables	76,918	73,152
Allowance for credit losses	(1,321)	(1,195)
Finance Receivables, Net [Member] | Dealer financing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross finance receivables	11,065	10,298
Allowance for credit losses	$ (45)	$ (51)