Finance Receivables, Net - Schedule of Amortized Cost Basis of Retail Loan Portfolio and Dealer Products Portfolio by Credit Quality Indicator (Details) - USD ($) $ in Millions	Dec. 31, 2021	Mar. 31, 2021
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	$ 1,683	$ 2,400
Year two, originated, fiscal year before current fiscal year	1,687	703
Year three, originated, two years before current fiscal year	496	805
Year four, originated, three years before current fiscal year	730	431
Year five, originated, four years before current fiscal year	332	455
Originated, more than five years before current fiscal year	1,637	1,804
Revolving loans	3,689	7,044
Total	10,254	13,642
Retail Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	25,396	32,228
Year two, originated, fiscal year before current fiscal year	24,862	16,249
Year three, originated, two years before current fiscal year	11,162	9,127
Year four, originated, three years before current fiscal year	5,796	6,090
Year five, originated, four years before current fiscal year	3,504	2,497
Originated, more than five years before current fiscal year	1,136	537
Total	71,856	66,728
Current [Member] | Retail Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	25,098	32,026
Year two, originated, fiscal year before current fiscal year	24,373	16,047
Year three, originated, two years before current fiscal year	10,913	8,972
Year four, originated, three years before current fiscal year	5,626	5,977
Year five, originated, four years before current fiscal year	3,390	2,435
Originated, more than five years before current fiscal year	1,057	496
Total	70,457	65,953
30-59 Days Past Due [Member] | Retail Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	215	147
Year two, originated, fiscal year before current fiscal year	341	145
Year three, originated, two years before current fiscal year	177	114
Year four, originated, three years before current fiscal year	119	83
Year five, originated, four years before current fiscal year	81	46
Originated, more than five years before current fiscal year	52	27
Total	985	562
60-89 Days Past Due [Member] | Retail Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	54	37
Year two, originated, fiscal year before current fiscal year	97	39
Year three, originated, two years before current fiscal year	49	28
Year four, originated, three years before current fiscal year	36	21
Year five, originated, four years before current fiscal year	22	11
Originated, more than five years before current fiscal year	16	8
Total	274	144
90 Days or Greater Past Due [Member] | Retail Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	29	18
Year two, originated, fiscal year before current fiscal year	51	18
Year three, originated, two years before current fiscal year	23	13
Year four, originated, three years before current fiscal year	15	9
Year five, originated, four years before current fiscal year	11	5
Originated, more than five years before current fiscal year	11	6
Total	140	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	2,866	6,157
Total	2,866	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	2,852	5,893
Total	2,852	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	12	218
Total	12	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	2	35
Total	2	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	1,164	1,895
Year two, originated, fiscal year before current fiscal year	1,318	369
Year three, originated, two years before current fiscal year	280	599
Year four, originated, three years before current fiscal year	568	389
Year five, originated, four years before current fiscal year	292	342
Originated, more than five years before current fiscal year	1,454	1,609
Revolving loans	0	0
Total	5,076	5,203
Real estate [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	1,164	1,874
Year two, originated, fiscal year before current fiscal year	1,316	320
Year three, originated, two years before current fiscal year	280	596
Year four, originated, three years before current fiscal year	568	356
Year five, originated, four years before current fiscal year	292	312
Originated, more than five years before current fiscal year	1,434	1,493
Revolving loans	0	0
Total	5,054	4,951
Real estate [Member] | Credit Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	0	8
Year two, originated, fiscal year before current fiscal year	2	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	12	99
Revolving loans	0	0
Total	14	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	8	17
Revolving loans	0	0
Total	8	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	519	505
Year two, originated, fiscal year before current fiscal year	369	334
Year three, originated, two years before current fiscal year	216	206
Year four, originated, three years before current fiscal year	162	42
Year five, originated, four years before current fiscal year	40	113
Originated, more than five years before current fiscal year	183	195
Revolving loans	823	887
Total	2,312	2,282
Working capital [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	519	503
Year two, originated, fiscal year before current fiscal year	368	334
Year three, originated, two years before current fiscal year	216	200
Year four, originated, three years before current fiscal year	162	41
Year five, originated, four years before current fiscal year	40	106
Originated, more than five years before current fiscal year	183	176
Revolving loans	823	878
Total	2,311	2,238
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	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	1	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