v3.26.1
Leases - Disclosure of Quantitative Information about Right-of-Use Assets (Detail) - JPY (¥)
¥ in Millions
12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Disclosure of quantitative information about right-of-use assets [line items]    
Net carrying amount ¥ 362,647 ¥ 384,835
Depreciation 91,198 97,102
Land and buildings [member]    
Disclosure of quantitative information about right-of-use assets [line items]    
Net carrying amount 313,222 335,499
Depreciation 71,912 73,160
Other assets [member]    
Disclosure of quantitative information about right-of-use assets [line items]    
Net carrying amount 49,425 49,336
Depreciation ¥ 19,286 ¥ 23,942