v3.26.1
Fair Value Measurements (Recorded Amounts of Major Financial Assets and Liabilities Measured at Fair Value on Recurring Basis) (Parenthetical) (Detail) - JPY (¥)
¥ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Aggregate loan fair value ¥ 78,020 ¥ 97,694  
Other assets 1,163 2,586  
Policy liabilities and Policy Account Balances 138,027 136,257  
Reinsurance recoverables      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Other assets 1,163 2,586  
Variable Annuity and Variable Life Insurance Contracts      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Policy liabilities and Policy Account Balances 138,027 136,257  
Fair Value, Measurements, Recurring      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Aggregate loan fair value [1] 78,020 97,694  
Other assets 1,163 2,586  
Policy liabilities and Policy Account Balances 138,027 136,257  
Fair Value, Measurements, Recurring | Reinsurance recoverables      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Other assets [2] 1,163 2,586  
Fair Value, Measurements, Recurring | Variable Annuity and Variable Life Insurance Contracts      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Policy liabilities and Policy Account Balances [3] 138,027 136,257  
Fair Value, Measurements, Recurring | Loans Held-for-Sale      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Gain (losses) from change in fair value (4,142) (1,052) ¥ 428
Gains (losses) from changes in instrument-specific credit risk 0 0 0
Aggregate unpaid loan principal balance 79,364 98,135  
Aggregate loan fair value 78,020 97,694  
Amount by which aggregate fair value of loan was less than aggregate unpaid loan principal balance 1,344 441  
Fair Value, Measurements, Recurring | Japanese and foreign government bond securities      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Gain (losses) from change in fair value 137 (59) (6)
Fair Value, Measurements, Recurring | Japanese and foreign government bond securities | Fair value option      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Amounts aggregate fair value elected fair value option 3,024 5,379  
Fair Value, Measurements, Recurring | Corporate debt securities      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Gain (losses) from change in fair value 362 441 399
Fair Value, Measurements, Recurring | Corporate debt securities | Fair value option      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Amounts aggregate fair value elected fair value option 11,927 10,679  
Fair Value, Measurements, Recurring | Equity securities      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Gain (losses) from change in fair value 1,038 1,954 ¥ 3,269
Fair Value, Measurements, Recurring | Equity securities | Fair value option      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Amounts aggregate fair value elected fair value option 24,845 24,960  
Amounts investment funds measured at net asset value per share are not included in above tables 168,854 118,666  
Fair Value, Measurements, Recurring | 90 Days or More Past Due | Loans Held-for-Sale      
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]      
Aggregate unpaid loan principal balance 9,858 17,098  
Aggregate loan fair value 8,657 16,346  
Amount by which aggregate fair value of loan was less than aggregate unpaid loan principal balance ¥ 1,201 ¥ 752  
[1] A certain subsidiary elected the fair value option on certain loans held for sale. These loans are multi-family and seniors housing loans and are sold to Federal National Mortgage Association (“Fannie Mae”), Federal Home Loan Mortgage Corporation (“Freddie Mac”) and institutional investors. Included in “Other (income) and expense” in the consolidated statements of income were a gain of ¥428 million, a loss of ¥1,052 million and a loss of ¥4,142 million from the change in the fair value of the loans for fiscal 2024, 2025 and 2026, respectively. No gains or losses were recognized in earnings during fiscal 2024, 2025 and 2026 attributable to changes in instrument-specific credit risk. The amounts of aggregate unpaid principal balance and aggregate fair value of the loans held for sale as of March 31, 2025, were ¥98,135 million and ¥97,694 million, respectively, and the amount of the aggregate fair value was less than the amount of aggregate unpaid principal balance by ¥441 million. The amounts of aggregate unpaid principal balance and aggregate fair value of the loans held for sale as of March 31, 2026, were ¥79,364 million and ¥78,020 million, respectively, and the amount of the aggregate fair value was less than the amount of aggregate unpaid principal balance by ¥1,344 million. The amounts of aggregate unpaid principal balance and aggregate fair value of loans that are 90 days or more past due or, in non-accrual status as of March 31, 2025, were ¥17,098 million and ¥16,346 million, respectively, and the amount of the aggregate fair value was less than the amount of aggregate unpaid principal balance by ¥752 million. The amounts of aggregate unpaid principal balance and aggregate fair value of loans that are 90 days or more past due or, in non-accrual status as of March 31, 2026, were ¥9,858 million and ¥8,657 million, respectively, and the amount of the aggregate fair value was less than the amount of aggregate unpaid principal balance by ¥1,201 million.
[2] Certain subsidiaries elected the fair value option for certain reinsurance contracts held. The fair value of the reinsurance contracts elected for the fair value option in other assets were ¥2,586 million and ¥1,163 million as of March 31, 2025 and 2026, respectively. For the effect of changes in the fair value of those reinsurance contracts on earnings for fiscal 2024, 2025 and 2026, see Note 23 “Income and Expenses Relating to Life Insurance Operations.”
[3] Certain subsidiaries elected the fair value option for the entire variable annuity and variable life insurance contracts held. The fair value of the variable annuity and variable life insurance contracts elected for the fair value option in policy liabilities and policy account balances were ¥136,257 million and ¥138,027 million as of March 31, 2025 and 2026, respectively. For the effect of changes in the fair value of the variable annuity and variable life insurance contracts on earnings for fiscal 2024, 2025 and 2026, see Note 23 “Income and Expenses Relating to Life Insurance Operations.”