Finance Receivables - Summary of Aging Analysis of Past Due Finance Receivables (Detail) - USD ($) $ in Millions | Sep. 30, 2023 | Mar. 31, 2023 |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | $ 43,036 | $ 37,838 |
Retail loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 40,030 | 35,002 |
Retail loans | New auto | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 31,376 | 27,751 |
Retail loans | Used and certified auto | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 7,304 | 6,004 |
Retail loans | Motorcycle and other | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 1,350 | 1,247 |
Dealer loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 3,006 | 2,836 |
Dealer loans | Wholesale flooring | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 1,967 | 1,946 |
Dealer loans | Commercial loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 1,039 | 890 |
Total past due | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 577 | 427 |
Total past due | Retail loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 576 | 427 |
Total past due | Retail loans | New auto | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 357 | 272 |
Total past due | Retail loans | Used and certified auto | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 193 | 134 |
Total past due | Retail loans | Motorcycle and other | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 26 | 21 |
Total past due | Dealer loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 1 | 0 |
Total past due | Dealer loans | Wholesale flooring | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 1 | 0 |
Total past due | Dealer loans | Commercial loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 0 | 0 |
30 – 59 days past due | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 416 | 334 |
30 – 59 days past due | Retail loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 415 | 334 |
30 – 59 days past due | Retail loans | New auto | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 261 | 217 |
30 – 59 days past due | Retail loans | Used and certified auto | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 138 | 103 |
30 – 59 days past due | Retail loans | Motorcycle and other | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 16 | 14 |
30 – 59 days past due | Dealer loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 1 | 0 |
30 – 59 days past due | Dealer loans | Wholesale flooring | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 1 | 0 |
30 – 59 days past due | Dealer loans | Commercial loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 0 | 0 |
60 – 89 days past due | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 127 | 74 |
60 – 89 days past due | Retail loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 127 | 74 |
60 – 89 days past due | Retail loans | New auto | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 77 | 44 |
60 – 89 days past due | Retail loans | Used and certified auto | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 43 | 25 |
60 – 89 days past due | Retail loans | Motorcycle and other | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 7 | 5 |
60 – 89 days past due | Dealer loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 0 | 0 |
60 – 89 days past due | Dealer loans | Wholesale flooring | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 0 | 0 |
60 – 89 days past due | Dealer loans | Commercial loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 0 | 0 |
90 days or greater past due | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 34 | 19 |
90 days or greater past due | Retail loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 34 | 19 |
90 days or greater past due | Retail loans | New auto | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 19 | 11 |
90 days or greater past due | Retail loans | Used and certified auto | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 12 | 6 |
90 days or greater past due | Retail loans | Motorcycle and other | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 3 | 2 |
90 days or greater past due | Dealer loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 0 | 0 |
90 days or greater past due | Dealer loans | Wholesale flooring | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 0 | 0 |
90 days or greater past due | Dealer loans | Commercial loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 0 | 0 |
Current or less than 30 days past due | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 42,459 | 37,411 |
Current or less than 30 days past due | Retail loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 39,454 | 34,575 |
Current or less than 30 days past due | Retail loans | New auto | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 31,019 | 27,479 |
Current or less than 30 days past due | Retail loans | Used and certified auto | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 7,111 | 5,870 |
Current or less than 30 days past due | Retail loans | Motorcycle and other | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 1,324 | 1,226 |
Current or less than 30 days past due | Dealer loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 3,005 | 2,836 |
Current or less than 30 days past due | Dealer loans | Wholesale flooring | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 1,966 | 1,946 |
Current or less than 30 days past due | Dealer loans | Commercial loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | $ 1,039 | $ 890 |