v3.26.1
Financing receivables - Changes in total allowance for CECL (Detail) - JPY (¥)
¥ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Allowances for current expected credit losses [Roll Forward]      
Opening balance, Allowances for current expected credit losses ¥ 2,544 ¥ 2,416 ¥ 4,056
Provision for credit losses, Allowances for current expected credit losses 104 164 30 [1]
Write-offs, Allowances for current expected credit losses (1,908)
Other, Allowances for current expected credit losses [2] 139 (36) 238
Ending balance, Allowances for current expected credit losses 2,787 2,544 2,416
Allowances against receivables other than loans [Roll Forward]      
Opening balance, Allowances against receivables other than loans [3] 14,376 15,631 1,776
Provision for credit losses, Allowances against receivables other than loans [3] 192 (876) 13,608 [1]
Write-offs, Allowances against receivables other than loans [3]
Other, Allowances against receivables other than loans [2],[3] 1,026 (379) 247
Ending balance, Allowances against receivables other than loans [3] 15,594 14,376 15,631
Total allowances for current expected credit losses [Roll Forward]      
Opening balance, Total allowances for current expected credit losses 16,920 18,047 5,832
Provision for credit losses, Total allowances for current expected credit losses 296 (712) 13,638 [1]
Write-offs, Total allowances for current expected credit losses (1,908)
Other, Total allowances for current expected credit losses [2] 1,165 (415) 485
Ending balance, Total allowances for current expected credit losses 18,381 16,920 18,047
Loans at banks [Member]      
Allowances for current expected credit losses [Roll Forward]      
Opening balance, Allowances for current expected credit losses 885 785 1,126
Provision for credit losses, Allowances for current expected credit losses (549) 100 (341) [1]
Write-offs, Allowances for current expected credit losses
Other, Allowances for current expected credit losses [2]
Ending balance, Allowances for current expected credit losses 336 885 785
Short-term secured margin loans [Member]      
Allowances for current expected credit losses [Roll Forward]      
Opening balance, Allowances for current expected credit losses  
Provision for credit losses, Allowances for current expected credit losses  
Write-offs, Allowances for current expected credit losses  
Other, Allowances for current expected credit losses [2]  
Ending balance, Allowances for current expected credit losses
Corporate loans [Member]      
Allowances for current expected credit losses [Roll Forward]      
Opening balance, Allowances for current expected credit losses 1,659 1,631 2,930
Provision for credit losses, Allowances for current expected credit losses 653 64 371 [1]
Write-offs, Allowances for current expected credit losses (1,908)
Other, Allowances for current expected credit losses [2] 139 (36) 238
Ending balance, Allowances for current expected credit losses ¥ 2,451 ¥ 1,659 ¥ 1,631
[1] A provision for credit losses in connection with settlement failures with a broker counterparty was recognized during the year ended March 31, 2024.
[2] Primarily includes recoveries and foreign exchange movements. The amounts of recoveries for the year ended March 31, 2024 and 2025 and 2026 were not significant.
[3] Includes amounts recognized against collateralized agreements, customer contract assets and receivables and other receivables.