v3.26.1
Installment Loans - Additional Information (Detail) - JPY (¥)
¥ in Millions
12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Interest income on loans ¥ 211,379 ¥ 188,294 ¥ 205,734
Loans held for sale in installment loans 105,720 111,527  
Loans held for sale measured at fair value 78,020 97,694  
Installment loans 4,173,582 4,081,019  
Purchased loans      
Accounts, Notes, Loans and Financing Receivable [Line Items]      
Installment loans 16,214 21,389  
Fair value at the acquisition date of purchased loans acquired during the period ¥ 10,818 ¥ 5,264