Finance Receivables, Net - Schedule of Amortized Cost Basis of Retail Loan Portfolio and Dealer Products Portfolio by Credit Quality Indicator (Details) - USD ($) $ in Millions	Sep. 30, 2022	Mar. 31, 2022
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	$ 842	$ 2,279
Year two, originated, fiscal year before current fiscal year	1,944	1,567
Year three, originated, two years before current fiscal year	1,432	473
Year four, originated, three years before current fiscal year	313	542
Year five, originated, four years before current fiscal year	466	297
Originated, more than five years before current fiscal year	1,276	1,423
Revolving loans	4,792	3,717
Total	11,065	10,298
Retail Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	18,516	32,758
Year two, originated, fiscal year before current fiscal year	27,628	22,342
Year three, originated, two years before current fiscal year	18,109	9,834
Year four, originated, three years before current fiscal year	7,552	4,913
Year five, originated, four years before current fiscal year	3,448	2,761
Originated, more than five years before current fiscal year	1,938	772
Total	77,191	73,380
Current [Member] | Retail Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	18,374	32,382
Year two, originated, fiscal year before current fiscal year	27,031	21,917
Year three, originated, two years before current fiscal year	17,651	9,624
Year four, originated, three years before current fiscal year	7,349	4,774
Year five, originated, four years before current fiscal year	3,326	2,674
Originated, more than five years before current fiscal year	1,834	718
Total	75,565	72,089
30-59 Days Past Due [Member] | Retail Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	103	275
Year two, originated, fiscal year before current fiscal year	406	304
Year three, originated, two years before current fiscal year	317	153
Year four, originated, three years before current fiscal year	142	101
Year five, originated, four years before current fiscal year	84	63
Originated, more than five years before current fiscal year	69	36
Total	1,121	932
60-89 Days Past Due [Member] | Retail Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	27	68
Year two, originated, fiscal year before current fiscal year	124	82
Year three, originated, two years before current fiscal year	95	40
Year four, originated, three years before current fiscal year	42	25
Year five, originated, four years before current fiscal year	26	16
Originated, more than five years before current fiscal year	21	11
Total	335	242
90 Days or Greater Past Due [Member] | Retail Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	12	33
Year two, originated, fiscal year before current fiscal year	67	39
Year three, originated, two years before current fiscal year	46	17
Year four, originated, three years before current fiscal year	19	13
Year five, originated, four years before current fiscal year	12	8
Originated, more than five years before current fiscal year	14	7
Total	170	117
Wholesale [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	0	0
Year two, originated, fiscal year before current fiscal year	0	0
Year three, originated, two years before current fiscal year	0	0
Year four, originated, three years before current fiscal year	0	0
Year five, originated, four years before current fiscal year	0	0
Originated, more than five years before current fiscal year	0	0
Revolving loans	3,460	2,943
Total	3,460	2,943
Wholesale [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	0	0
Year two, originated, fiscal year before current fiscal year	0	0
Year three, originated, two years before current fiscal year	0	0
Year four, originated, three years before current fiscal year	0	0
Year five, originated, four years before current fiscal year	0	0
Originated, more than five years before current fiscal year	0	0
Revolving loans	3,444	2,927
Total	3,444	2,927
Wholesale [Member] | Credit Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	0	0
Year two, originated, fiscal year before current fiscal year	0	0
Year three, originated, two years before current fiscal year	0	0
Year four, originated, three years before current fiscal year	0	0
Year five, originated, four years before current fiscal year	0	0
Originated, more than five years before current fiscal year	0	0
Revolving loans	16	16
Total	16	16
Wholesale [Member] | At Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	0	0
Year two, originated, fiscal year before current fiscal year	0	0
Year three, originated, two years before current fiscal year	0	0
Year four, originated, three years before current fiscal year	0	0
Year five, originated, four years before current fiscal year	0	0
Originated, more than five years before current fiscal year	0	0
Revolving loans	0	0
Total	0	0
Wholesale [Member] | Default [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	0	0
Year two, originated, fiscal year before current fiscal year	0	0
Year three, originated, two years before current fiscal year	0	0
Year four, originated, three years before current fiscal year	0	0
Year five, originated, four years before current fiscal year	0	0
Originated, more than five years before current fiscal year	0	0
Revolving loans	0	0
Total	0	0
Real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	563	1,616
Year two, originated, fiscal year before current fiscal year	1,424	1,245
Year three, originated, two years before current fiscal year	1,149	264
Year four, originated, three years before current fiscal year	158	384
Year five, originated, four years before current fiscal year	335	260
Originated, more than five years before current fiscal year	1,140	1,250
Revolving loans	138	0
Total	4,907	5,019
Real estate [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	558	1,614
Year two, originated, fiscal year before current fiscal year	1,424	1,245
Year three, originated, two years before current fiscal year	1,149	264
Year four, originated, three years before current fiscal year	158	384
Year five, originated, four years before current fiscal year	335	260
Originated, more than five years before current fiscal year	1,140	1,245
Revolving loans	138	0
Total	4,902	5,012
Real estate [Member] | Credit Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	5	2
Year two, originated, fiscal year before current fiscal year	0	0
Year three, originated, two years before current fiscal year	0	0
Year four, originated, three years before current fiscal year	0	0
Year five, originated, four years before current fiscal year	0	0
Originated, more than five years before current fiscal year	0	5
Revolving loans	0	0
Total	5	7
Real estate [Member] | At Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	0	0
Year two, originated, fiscal year before current fiscal year	0	0
Year three, originated, two years before current fiscal year	0	0
Year four, originated, three years before current fiscal year	0	0
Year five, originated, four years before current fiscal year	0	0
Originated, more than five years before current fiscal year	0	0
Revolving loans	0	0
Total	0	0
Real estate [Member] | Default [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	0	0
Year two, originated, fiscal year before current fiscal year	0	0
Year three, originated, two years before current fiscal year	0	0
Year four, originated, three years before current fiscal year	0	0
Year five, originated, four years before current fiscal year	0	0
Originated, more than five years before current fiscal year	0	0
Revolving loans	0	0
Total	0	0
Working capital [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	279	663
Year two, originated, fiscal year before current fiscal year	520	322
Year three, originated, two years before current fiscal year	283	209
Year four, originated, three years before current fiscal year	155	158
Year five, originated, four years before current fiscal year	131	37
Originated, more than five years before current fiscal year	136	173
Revolving loans	1,194	774
Total	2,698	2,336
Working capital [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	279	662
Year two, originated, fiscal year before current fiscal year	520	321
Year three, originated, two years before current fiscal year	283	209
Year four, originated, three years before current fiscal year	155	158
Year five, originated, four years before current fiscal year	131	37
Originated, more than five years before current fiscal year	136	173
Revolving loans	1,194	774
Total	2,698	2,334
Working capital [Member] | Credit Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	0	1
Year two, originated, fiscal year before current fiscal year	0	1
Year three, originated, two years before current fiscal year	0	0
Year four, originated, three years before current fiscal year	0	0
Year five, originated, four years before current fiscal year	0	0
Originated, more than five years before current fiscal year	0	0
Revolving loans	0	0
Total	0	2
Working capital [Member] | At Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	0	0
Year two, originated, fiscal year before current fiscal year	0	0
Year three, originated, two years before current fiscal year	0	0
Year four, originated, three years before current fiscal year	0	0
Year five, originated, four years before current fiscal year	0	0
Originated, more than five years before current fiscal year	0	0
Revolving loans	0	0
Total	0	0
Working capital [Member] | Default [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	0	0
Year two, originated, fiscal year before current fiscal year	0	0
Year three, originated, two years before current fiscal year	0	0
Year four, originated, three years before current fiscal year	0	0
Year five, originated, four years before current fiscal year	0	0
Originated, more than five years before current fiscal year	0	0
Revolving loans	0	0
Total	$ 0	$ 0