Finance Receivables - Summary of Aging Analysis of Past Due Finance Receivables (Detail) - USD ($) $ in Millions | Jun. 30, 2024 | Mar. 31, 2024 |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | $ 49,569 | $ 47,601 |
Retail loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 45,338 | 43,541 |
Retail loans | New automobile | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 35,571 | 34,185 |
Retail loans | Used and certified automobile | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 8,292 | 7,991 |
Retail loans | Motorcycle and other | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 1,475 | 1,365 |
Dealer loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 4,231 | 4,060 |
Dealer loans | Wholesale flooring | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 2,868 | 2,786 |
Dealer loans | Commercial loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 1,363 | 1,274 |
Total past due | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 596 | 528 |
Total past due | Retail loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 595 | 527 |
Total past due | Retail loans | New automobile | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 366 | 327 |
Total past due | Retail loans | Used and certified automobile | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 203 | 176 |
Total past due | Retail loans | Motorcycle and other | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 26 | 24 |
Total past due | Dealer loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 1 | 1 |
Total past due | Dealer loans | Wholesale flooring | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 1 | 1 |
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 | 446 | 403 |
30 – 59 days past due | Retail loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 445 | 402 |
30 – 59 days past due | Retail loans | New automobile | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 282 | 253 |
30 – 59 days past due | Retail loans | Used and certified automobile | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 148 | 134 |
30 – 59 days past due | Retail loans | Motorcycle and other | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 15 | 15 |
30 – 59 days past due | Dealer loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 1 | 1 |
30 – 59 days past due | Dealer loans | Wholesale flooring | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 1 | 1 |
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 | 120 | 98 |
60 – 89 days past due | Retail loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 120 | 98 |
60 – 89 days past due | Retail loans | New automobile | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 69 | 59 |
60 – 89 days past due | Retail loans | Used and certified automobile | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 44 | 33 |
60 – 89 days past due | Retail loans | Motorcycle and other | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 7 | 6 |
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 | 30 | 27 |
90 days or greater past due | Retail loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 30 | 27 |
90 days or greater past due | Retail loans | New automobile | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 15 | 15 |
90 days or greater past due | Retail loans | Used and certified automobile | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 11 | 9 |
90 days or greater past due | Retail loans | Motorcycle and other | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 4 | 3 |
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 | 48,973 | 47,073 |
Current or less than 30 days past due | Retail loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 44,743 | 43,014 |
Current or less than 30 days past due | Retail loans | New automobile | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 35,205 | 33,858 |
Current or less than 30 days past due | Retail loans | Used and certified automobile | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 8,089 | 7,815 |
Current or less than 30 days past due | Retail loans | Motorcycle and other | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 1,449 | 1,341 |
Current or less than 30 days past due | Dealer loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 4,230 | 4,059 |
Current or less than 30 days past due | Dealer loans | Wholesale flooring | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | 2,867 | 2,785 |
Current or less than 30 days past due | Dealer loans | Commercial loans | | |
Financing Receivable, Past Due [Line Items] | | |
Total finance receivables | $ 1,363 | $ 1,274 |