Finance Receivables, Net - Schedule of Amortized Cost Basis of Retail Loan Portfolio and Dealer Products Portfolio by Credit Quality Indicator (Details) - USD ($) $ in Millions	9 Months Ended
	Dec. 31, 2023	Mar. 31, 2023
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	$ 1,417	$ 2,180
Year two, originated, fiscal year before current fiscal year	1,689	1,349
Year three, originated, two years before current fiscal year	1,174	1,241
Year four, originated, three years before current fiscal year	1,081	264
Year five, originated, four years before current fiscal year	239	424
Originated, more than five years before current fiscal year	1,018	940
Revolving loans	9,761	5,725
Total	16,379	12,123
Retail Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	28,315	32,820
Year two, originated, fiscal year before current fiscal year	25,489	23,222
Year three, originated, two years before current fiscal year	17,410	14,678
Year four, originated, three years before current fiscal year	10,228	5,731
Year five, originated, four years before current fiscal year	3,449	2,279
Originated, more than five years before current fiscal year	1,219	916
Total	86,110	79,646
Gross Charge-Offs, year one, originated, current fiscal year	10
Gross Charge-Offs, Year two, originated, fiscal year before current fiscal year	198
Gross Charge-Offs, Year three, originated, two years before current fiscal year	191
Gross Charge-Offs, Year four, originated, three years before current fiscal year	82
Gross Charge-Offs, Year five, originated, four years before current fiscal year	29
Gross Charge-Offs, Originated, more than five years before current fiscal year	26
Gross Charge-Offs, Total	536
Current [Member] | Retail Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	27,968	32,377
Year two, originated, fiscal year before current fiscal year	24,650	22,585
Year three, originated, two years before current fiscal year	16,640	14,278
Year four, originated, three years before current fiscal year	9,777	5,555
Year five, originated, four years before current fiscal year	3,279	2,178
Originated, more than five years before current fiscal year	1,098	846
Total	83,412	77,819
30-59 Days Past Due [Member] | Retail Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	253	306
Year two, originated, fiscal year before current fiscal year	582	439
Year three, originated, two years before current fiscal year	537	285
Year four, originated, three years before current fiscal year	319	125
Year five, originated, four years before current fiscal year	120	71
Originated, more than five years before current fiscal year	78	44
Total	1,889	1,270
60-89 Days Past Due [Member] | Retail Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	62	90
Year two, originated, fiscal year before current fiscal year	168	135
Year three, originated, two years before current fiscal year	159	82
Year four, originated, three years before current fiscal year	91	35
Year five, originated, four years before current fiscal year	35	21
Originated, more than five years before current fiscal year	27	15
Total	542	378
90 Days or Greater Past Due [Member] | Retail Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	32	47
Year two, originated, fiscal year before current fiscal year	89	63
Year three, originated, two years before current fiscal year	74	33
Year four, originated, three years before current fiscal year	41	16
Year five, originated, four years before current fiscal year	15	9
Originated, more than five years before current fiscal year	16	11
Total	267	179
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	7,143	3,964
Total	7,143	3,964
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	6,912	3,859
Total	6,912	3,859
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	139	54
Total	139	54
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	81	51
Total	81	51
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	11	0
Total	11	0
Real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	894	1,391
Year two, originated, fiscal year before current fiscal year	1,089	1,031
Year three, originated, two years before current fiscal year	910	1,059
Year four, originated, three years before current fiscal year	929	133
Year five, originated, four years before current fiscal year	129	300
Originated, more than five years before current fiscal year	850	852
Revolving loans	13	209
Total	4,814	4,975
Real estate [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	868	1,378
Year two, originated, fiscal year before current fiscal year	1,084	1,024
Year three, originated, two years before current fiscal year	899	1,057
Year four, originated, three years before current fiscal year	897	133
Year five, originated, four years before current fiscal year	129	300
Originated, more than five years before current fiscal year	849	850
Revolving loans	13	209
Total	4,739	4,951
Real estate [Member] | Credit Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	26	5
Year two, originated, fiscal year before current fiscal year	5	0
Year three, originated, two years before current fiscal year	4	2
Year four, originated, three years before current fiscal year	8	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	43	7
Real estate [Member] | At Risk [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	0	8
Year two, originated, fiscal year before current fiscal year	0	7
Year three, originated, two years before current fiscal year	7	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	1	2
Revolving loans	0	0
Total	8	17
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	24	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	24	0
Working capital [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	523	789
Year two, originated, fiscal year before current fiscal year	600	318
Year three, originated, two years before current fiscal year	264	182
Year four, originated, three years before current fiscal year	152	131
Year five, originated, four years before current fiscal year	110	124
Originated, more than five years before current fiscal year	168	88
Revolving loans	2,605	1,552
Total	4,422	3,184
Working capital [Member] | Performing [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	512	789
Year two, originated, fiscal year before current fiscal year	598	317
Year three, originated, two years before current fiscal year	263	182
Year four, originated, three years before current fiscal year	139	131
Year five, originated, four years before current fiscal year	110	124
Originated, more than five years before current fiscal year	168	88
Revolving loans	2,604	1,552
Total	4,394	3,183
Working capital [Member] | Credit Watch [Member]
Financing Receivable, Recorded Investment [Line Items]
Year one, originated, current fiscal year	11	0
Year two, originated, fiscal year before current fiscal year	2	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	1	0
Total	14	0
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	1
Year three, originated, two years before current fiscal year	1	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	1	1
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	13	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	$ 13	$ 0