Finance Receivables, Net - Schedule of Amortized Cost Basis of Retail Loan Portfolio and Dealer Products Portfolio by Credit Quality Indicator (Details) - USD ($) $ in Millions	Mar. 31, 2022	Mar. 31, 2021
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	$ 2,279	$ 2,400
Year two, originated, fiscal year before current fiscal year	1,567	703
Year three, originated, two years before current fiscal year	473	805
Year four, originated, three years before current fiscal year	542	431
Year five, originated, four years before current fiscal year	297	455
Originated, more than five years before current fiscal year	1,423	1,804
Revolving loans	3,717	7,044
Total	10,298	13,642
Retail Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	32,758	32,228
Year two, originated, fiscal year before current fiscal year	22,342	16,249
Year three, originated, two years before current fiscal year	9,834	9,127
Year four, originated, three years before current fiscal year	4,913	6,090
Year five, originated, four years before current fiscal year	2,761	2,497
Originated, more than five years before current fiscal year	772	537
Total	73,380	66,728
Current [Member] | Retail Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	32,382	32,026
Year two, originated, fiscal year before current fiscal year	21,917	16,047
Year three, originated, two years before current fiscal year	9,624	8,972
Year four, originated, three years before current fiscal year	4,774	5,977
Year five, originated, four years before current fiscal year	2,674	2,435
Originated, more than five years before current fiscal year	718	496
Total	72,089	65,953
30-59 Days Past Due [Member] | Retail Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	275	147
Year two, originated, fiscal year before current fiscal year	304	145
Year three, originated, two years before current fiscal year	153	114
Year four, originated, three years before current fiscal year	101	83
Year five, originated, four years before current fiscal year	63	46
Originated, more than five years before current fiscal year	36	27
Total	932	562
60-89 Days Past Due [Member] | Retail Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	68	37
Year two, originated, fiscal year before current fiscal year	82	39
Year three, originated, two years before current fiscal year	40	28
Year four, originated, three years before current fiscal year	25	21
Year five, originated, four years before current fiscal year	16	11
Originated, more than five years before current fiscal year	11	8
Total	242	144
90 Days or Greater Past Due [Member] | Retail Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	33	18
Year two, originated, fiscal year before current fiscal year	39	18
Year three, originated, two years before current fiscal year	17	13
Year four, originated, three years before current fiscal year	13	9
Year five, originated, four years before current fiscal year	8	5
Originated, more than five years before current fiscal year	7	6
Total	117	69
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	2,943	6,157
Total	2,943	6,157
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	2,927	5,893
Total	2,927	5,893
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	218
Total	16	218
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	35
Total	0	35
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	11
Total	0	11
Real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	1,616	1,895
Year two, originated, fiscal year before current fiscal year	1,245	369
Year three, originated, two years before current fiscal year	264	599
Year four, originated, three years before current fiscal year	384	389
Year five, originated, four years before current fiscal year	260	342
Originated, more than five years before current fiscal year	1,250	1,609
Revolving loans	0	0
Total	5,019	5,203
Real estate [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	1,614	1,874
Year two, originated, fiscal year before current fiscal year	1,245	320
Year three, originated, two years before current fiscal year	264	596
Year four, originated, three years before current fiscal year	384	356
Year five, originated, four years before current fiscal year	260	312
Originated, more than five years before current fiscal year	1,245	1,493
Revolving loans	0	0
Total	5,012	4,951
Real estate [Member] | Credit Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	2	8
Year two, originated, fiscal year before current fiscal year	0	49
Year three, originated, two years before current fiscal year	0	3
Year four, originated, three years before current fiscal year	0	20
Year five, originated, four years before current fiscal year	0	9
Originated, more than five years before current fiscal year	5	99
Revolving loans	0	0
Total	7	188
Real estate [Member] | At Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	0	13
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	12
Originated, more than five years before current fiscal year	0	17
Revolving loans	0	0
Total	0	42
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	13
Year five, originated, four years before current fiscal year	0	9
Originated, more than five years before current fiscal year	0	0
Revolving loans	0	0
Total	0	22
Working capital [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	663	505
Year two, originated, fiscal year before current fiscal year	322	334
Year three, originated, two years before current fiscal year	209	206
Year four, originated, three years before current fiscal year	158	42
Year five, originated, four years before current fiscal year	37	113
Originated, more than five years before current fiscal year	173	195
Revolving loans	774	887
Total	2,336	2,282
Working capital [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	662	503
Year two, originated, fiscal year before current fiscal year	321	334
Year three, originated, two years before current fiscal year	209	200
Year four, originated, three years before current fiscal year	158	41
Year five, originated, four years before current fiscal year	37	106
Originated, more than five years before current fiscal year	173	176
Revolving loans	774	878
Total	2,334	2,238
Working capital [Member] | Credit Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	1	1
Year two, originated, fiscal year before current fiscal year	1	0
Year three, originated, two years before current fiscal year	0	6
Year four, originated, three years before current fiscal year	0	1
Year five, originated, four years before current fiscal year	0	0
Originated, more than five years before current fiscal year	0	19
Revolving loans	0	9
Total	2	36
Working capital [Member] | At Risk [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	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	7
Originated, more than five years before current fiscal year	0	0
Revolving loans	0	0
Total	0	8
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