v3.26.1
Pension and Other Employee Benefit Plans (Plans with Projected Benefit Obligations in Excess of Plan Assets and Plans with Accumulated Benefit Obligations in Excess of Plan Assets) (Detail) - JPY (¥)
¥ in Millions
Mar. 31, 2026
Mar. 31, 2025
Plans with projected benefit obligations in excess of plan assets:    
Projected benefit obligations ¥ 34,583 ¥ 28,770
Fair value of plan assets 11,477 4,675
Plans with accumulated benefit obligations in excess of plan assets:    
Accumulated benefit obligations 34,583 28,770
Fair value of plan assets ¥ 11,477 ¥ 4,675