Finance Receivables - Narrative (Detail) - USD ($) $ in Millions	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables	$ 45,535	$ 37,585	$ 35,817
Retail loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables	41,947	34,754
Collateral Pledged | Retail loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables	$ 9,200	$ 7,200