v3.26.1
Financial Instruments - Schedule of Gross Carrying Amounts Of Financial Assets Measured at Amortized Cost by Due Date (Details) - JPY (¥)
¥ in Millions
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 ¥ 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 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 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 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 48,379 45,846 ¥ 32,909
Credit Risk | Gross Carrying Amount      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 1,678,459 1,608,098  
Credit Risk | Gross Carrying Amount | Not past due      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 1,525,274 1,481,308  
Credit Risk | Gross Carrying Amount | Within 30 days      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 91,156 70,682  
Credit Risk | Gross Carrying Amount | Within 31 to 90 days      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 11,164 9,122  
Credit Risk | Gross Carrying Amount | Over 90 days      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 50,865 46,986  
Credit Risk | Financial assets that are purchased or originated credit-impaired | Gross Carrying Amount      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 14,965 11,581  
Credit Risk | Financial assets that are purchased or originated credit-impaired | Gross Carrying Amount | Within 30 days      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 82 95  
Credit Risk | Financial assets that are purchased or originated credit-impaired | Gross Carrying Amount | Within 31 to 90 days      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 1,673 1,383  
Credit Risk | Financial assets that are purchased or originated credit-impaired | Gross Carrying Amount | Over 90 days      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 13,210 10,103  
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 13,251 10,660 8,822
Credit Risk | Financial Assets with Loss Allowance Measured at 12-month ECL | Gross Carrying Amount      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 1,609,198 1,546,224  
Credit Risk | Financial Assets with Loss Allowance Measured at 12-month ECL | Gross Carrying Amount | Not past due      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 1,522,485 1,479,394  
Credit Risk | Financial Assets with Loss Allowance Measured at 12-month ECL | Gross Carrying Amount | Within 30 days      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 86,713 66,830  
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 1,985 1,572 1,308
Credit Risk | Financial Assets with Loss Allowance Measured at Lifetime ECL | Financial Assets with Significant Increase in Credit Risk Since Initial Recognition | Gross Carrying Amount      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 9,072 7,267  
Credit Risk | Financial Assets with Loss Allowance Measured at Lifetime ECL | Financial Assets with Significant Increase in Credit Risk Since Initial Recognition | Gross Carrying Amount | Within 30 days      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 3,128 2,781  
Credit Risk | Financial Assets with Loss Allowance Measured at Lifetime ECL | Financial Assets with Significant Increase in Credit Risk Since Initial Recognition | Gross Carrying Amount | Within 31 to 90 days      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 5,944 4,486  
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 32,720 33,110 22,190
Credit Risk | Financial Assets with Loss Allowance Measured at Lifetime ECL | Credit-Impaired Financial Assets | Gross Carrying Amount      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 41,955 40,587  
Credit Risk | Financial Assets with Loss Allowance Measured at Lifetime ECL | Credit-Impaired Financial Assets | Gross Carrying Amount | Within 30 days      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 1,159 948  
Credit Risk | Financial Assets with Loss Allowance Measured at Lifetime ECL | Credit-Impaired Financial Assets | Gross Carrying Amount | Within 31 to 90 days      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 3,519 3,250  
Credit Risk | Financial Assets with Loss Allowance Measured at Lifetime ECL | Credit-Impaired Financial Assets | Gross Carrying Amount | Over 90 days      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 37,277 36,389  
Credit Risk | Accounts Receivables for Which Simplified Approach is Applied | Financial Assets with Loss Allowance Measured at Lifetime ECL      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 423 504 ¥ 589
Credit Risk | Accounts Receivables for Which Simplified Approach is Applied | Financial Assets with Loss Allowance Measured at Lifetime ECL | Gross Carrying Amount      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 3,269 2,439  
Credit Risk | Accounts Receivables for Which Simplified Approach is Applied | Financial Assets with Loss Allowance Measured at Lifetime ECL | Gross Carrying Amount | Not past due      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 2,789 1,914  
Credit Risk | Accounts Receivables for Which Simplified Approach is Applied | Financial Assets with Loss Allowance Measured at Lifetime ECL | Gross Carrying Amount | Within 30 days      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 74 28  
Credit Risk | Accounts Receivables for Which Simplified Approach is Applied | Financial Assets with Loss Allowance Measured at Lifetime ECL | Gross Carrying Amount | Within 31 to 90 days      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets 28 3  
Credit Risk | Accounts Receivables for Which Simplified Approach is Applied | Financial Assets with Loss Allowance Measured at Lifetime ECL | Gross Carrying Amount | Over 90 days      
Disclosure of reconciliation of changes in loss allowance and explanation of changes in gross carrying amount for financial instruments [line items]      
Financial assets ¥ 378 ¥ 494