v3.26.1
Pension Plans (Summary of Projected Benefit Obligations and Fair Value of Plan Assets for Pension Plans) (Detail) - JPY (¥)
¥ in Millions
Mar. 31, 2026
Mar. 31, 2025
Japanese plans    
Defined Benefit Plan Disclosure [Line Items]    
Projected benefit obligations ¥ 14,572 ¥ 15,203
Fair value of plan assets 0 0
Overseas plans    
Defined Benefit Plan Disclosure [Line Items]    
Projected benefit obligations 2,308 3,844
Fair value of plan assets ¥ 366 ¥ 2,110