Finance Receivables, Net - Net Financing Receivables (Details) - USD ($) $ in Millions		Dec. 31, 2023	Mar. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross finance receivables		$ 102,489	$ 91,769
Allowance for credit losses		(1,605)	(1,489)
Finance receivables, net		100,884	90,280
Finance Receivables, Net [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross finance receivables		102,354	91,638
Deferred origination costs		1,417	1,315
Deferred income		(1,282)	(1,184)
Allowance for credit losses		(1,605)	(1,489)
Finance receivables, net		100,884	90,280
Finance Receivables, Net [Member] | Retail receivables [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross finance receivables	[1]	85,975	79,515
Allowance for credit losses		(1,533)	(1,430)
Finance Receivables, Net [Member] | Dealer financing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross finance receivables		16,379	12,123
Allowance for credit losses		$ (72)	$ (59)

[1] Includes gross securitized retail receivables of $30.1 billion and $29.0 billion as of December 31, 2023 and March 31, 2023, respectively.