Allowance for Credit Losses - Allowance for Credit Losses and Finance Receivables by Portfolio Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2023		Jun. 30, 2022
Financing Receivable Allowance For Credit Losses [Abstract]
Provision for credit losses	$ 165		$ 78
Retail loan [Member]
Financing Receivable Allowance For Credit Losses [Abstract]
Charge-offs	(134)
Finance Receivables, Net [Member]
Financing Receivable Allowance For Credit Losses [Abstract]
Allowance for credit losses at beginning of period	1,513		1,272
Charge-offs	(134)		(91)
Recoveries	29		15
Provision for credit losses	165		78
Allowance for credit losses at end of period	1,573	[1]	1,274	[2]
Finance Receivables, Net [Member] | Retail loan [Member]
Financing Receivable Allowance For Credit Losses [Abstract]
Allowance for credit losses at beginning of period	1,430		1,195
Charge-offs	(134)		(91)
Recoveries	29		15
Provision for credit losses	158		90
Allowance for credit losses at end of period	1,483	[1]	1,209	[2]
Finance Receivables, Net [Member] | Dealer products [Member]
Financing Receivable Allowance For Credit Losses [Abstract]
Allowance for credit losses at beginning of period	83		77
Charge-offs	0		0
Recoveries	0		0
Provision for credit losses	7		(12)
Allowance for credit losses at end of period	$ 90	[1]	$ 65	[2]

[1] Ending balance includes $28 million of allowance for credit losses recorded in Other liabilities on the Consolidated Balance Sheet which is related to off-balance sheet lending commitments in the dealer products portfolio.

[2] Ending balance includes $26 million of allowance for credit losses recorded in Other liabilities on the Consolidated Balance Sheet which is related to off-balance sheet lending commitments in the dealer products portfolio.