v3.26.1
Financial Instruments - Schedule of Movements in Loss Allowances for Financial Assets (Details) - JPY (¥)
¥ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets, beginning balance ¥ 2,146,595    
Write-offs (742) ¥ (690) ¥ (615)
Financial assets, ending balance 3,071,287 2,146,595  
Financial Assets with Loss Allowance Measured at 12-month ECL      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets, beginning balance 2,143,066    
Financial assets, ending balance 3,065,985 2,143,066  
Financial Assets with Loss Allowance Measured at Lifetime ECL | Financial Assets with Significant Increase in Credit Risk Since Initial Recognition      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets, beginning balance 1,849    
Financial assets, ending balance 2,279 1,849  
Financial Assets with Loss Allowance Measured at Lifetime ECL | Credit-Impaired Financial Assets      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets, beginning balance 1,680    
Financial assets, ending balance 3,023 1,680  
Credit Risk      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets, beginning balance 45,846 32,909  
Provision for loss allowance, net of reversal 4,798 3,848  
Write-offs (15,048) (15,953)  
Changes in risk variables 23,422 25,058  
Derecognition of receivables upon sale (10,598)    
Other (41) (16)  
Financial assets, ending balance 48,379 45,846 32,909
Credit Risk | Financial Assets with Loss Allowance Measured at 12-month ECL      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets, beginning balance 10,660 8,822  
Provision for loss allowance, net of reversal 4,838 3,851  
Write-offs (1,679) (1,621)  
Transfer between stages (126) (205)  
Changes in risk variables (448) (142)  
Other 6 (45)  
Financial assets, ending balance 13,251 10,660 8,822
Credit Risk | Financial Assets with Loss Allowance Measured at Lifetime ECL | Financial Assets with Significant Increase in Credit Risk Since Initial Recognition      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets, beginning balance 1,572 1,308  
Provision for loss allowance, net of reversal 27 81  
Write-offs (696) (709)  
Transfer between stages (782) (647)  
Changes in risk variables 1,864 1,539  
Financial assets, ending balance 1,985 1,572 1,308
Credit Risk | Financial Assets with Loss Allowance Measured at Lifetime ECL | Credit-Impaired Financial Assets      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets, beginning balance 33,110 22,190  
Provision for loss allowance, net of reversal 2    
Write-offs (12,661) (13,622)  
Transfer between stages 908 852  
Changes in risk variables 22,006 23,661  
Derecognition of receivables upon sale (10,598)    
Other (47) 29  
Financial assets, ending balance 32,720 33,110 22,190
Credit Risk | Financial Assets with Loss Allowance Measured at Lifetime ECL | Accounts Receivables for Which Simplified Approach is Applied      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets, beginning balance 504 589  
Provision for loss allowance, net of reversal (69) (84)  
Write-offs (12) (1)  
Financial assets, ending balance ¥ 423 ¥ 504 ¥ 589