Finance Receivables, Net - Net Financing Receivables (Details) - USD ($) $ in Millions	Mar. 31, 2022	Mar. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross finance receivables	$ 83,678	$ 80,370
Allowance for credit losses	(1,246)	(1,178)
Finance receivables, net	82,432	79,192
Finance Receivables, Net [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross finance receivables	83,450	80,633
Deferred origination costs	1,330	1,145
Deferred income	(1,102)	(1,408)
Allowance for credit losses	(1,246)	(1,178)
Finance receivables, net	82,432	79,192
Finance Receivables, Net [Member] | Retail receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross finance receivables	73,152	66,991
Allowance for credit losses	(1,195)	(1,075)
Finance Receivables, Net [Member] | Dealer financing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross finance receivables	10,298	13,642
Allowance for credit losses	$ (51)	$ (103)