v3.26.1
Financial Risks - Summary of Breakdown of Wholesale Receivables and Dealer Loan Receivables (Detail) - JPY (¥)
¥ in Millions
Mar. 31, 2026
Mar. 31, 2025
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loans ¥ 17,221,084 ¥ 17,638,825
Expected credit loss for 12 months [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loans 16,698,434 17,214,236
Expected credit loss for the entire period [Member] | Financial receivable not credit-impaired [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loans 473,331 411,202
Expected credit loss for the entire period [Member] | Credit-impaired financial receivable [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loans 49,319 13,387
Performing [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loans 5,369,936 4,478,021
Performing [Member] | Expected credit loss for 12 months [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loans 5,369,936 4,478,021
Credit Watch [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loans 360,782 357,379
Credit Watch [Member] | Expected credit loss for 12 months [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loans 132,379 213,400
Credit Watch [Member] | Expected credit loss for the entire period [Member] | Financial receivable not credit-impaired [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loans 228,403 143,979
At Risk [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loans 46,970 56,776
At Risk [Member] | Expected credit loss for the entire period [Member] | Financial receivable not credit-impaired [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loans 43,883 54,774
At Risk [Member] | Expected credit loss for the entire period [Member] | Credit-impaired financial receivable [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loans 3,086 2,003
Default [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loans 44,244 10,360
Default [Member] | Expected credit loss for the entire period [Member] | Credit-impaired financial receivable [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loans 44,244 10,360
Loan commitments [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loans 9,920,894 10,477,894
Loan commitments [Member] | Expected credit loss for 12 months [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loans 9,731,868 10,288,422
Loan commitments [Member] | Expected credit loss for the entire period [Member] | Financial receivable not credit-impaired [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loans 187,037 188,448
Loan commitments [Member] | Expected credit loss for the entire period [Member] | Credit-impaired financial receivable [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loans 1,989 1,024
Financial guarantee contracts [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loans 1,478,259 2,258,395
Financial guarantee contracts [Member] | Expected credit loss for 12 months [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loans 1,464,251 2,234,393
Financial guarantee contracts [Member] | Expected credit loss for the entire period [Member] | Financial receivable not credit-impaired [Member]    
Disclosure of breakdown of wholesale receivables and dealer loan receivables [Line items]    
Wholesale and other dealer loans ¥ 14,008 ¥ 24,001