v3.25.2
Employee Benefits - Summary of Changes in Present Value of the Defined Benefit Obligations (Details) - JPY (¥)
¥ in Millions
12 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Defined Benefit Plan, Change in Benefit Liability [Roll Forward]    
At beginning of the year ¥ 444,790  
Remeasurement of defined benefit pension plans    
At end of the year 384,488 ¥ 444,790
Japan    
Defined Benefit Plan, Change in Benefit Liability [Roll Forward]    
At beginning of the year 143,712  
Remeasurement of defined benefit pension plans    
At end of the year 130,864 143,712
Foreign    
Defined Benefit Plan, Change in Benefit Liability [Roll Forward]    
At beginning of the year 301,078  
Remeasurement of defined benefit pension plans    
At end of the year 253,624 301,078
Present value of defined benefit obligation    
Defined Benefit Plan, Change in Benefit Liability [Roll Forward]    
At beginning of the year 444,790 401,096
Current service cost 15,199 14,236
Interest cost 11,618 11,505
Remeasurement of defined benefit pension plans    
From changes in demographic assumptions 77 (143)
From changes in financial assumptions (11,574) 5,879
Experience adjustments 7,701 (4,202)
Past service cost (1,196) (67)
Settlement (57,537)  
Benefits paid (29,754) (22,257)
Contributions by the employees 5,053 4,610
Effect of business combinations and disposals (256)  
Foreign currency translation differences 366 34,132
At end of the year 384,488 444,790
Present value of defined benefit obligation | Japan    
Defined Benefit Plan, Change in Benefit Liability [Roll Forward]    
At beginning of the year 143,712 153,371
Current service cost 2,918 3,004
Interest cost 2,448 2,078
Remeasurement of defined benefit pension plans    
From changes in demographic assumptions 40 (341)
From changes in financial assumptions (7,622) (5,508)
Experience adjustments 696 426
Past service cost 1,535 0
Settlement 0  
Benefits paid (12,701) (9,318)
Contributions by the employees 0 0
Effect of business combinations and disposals (161)  
Foreign currency translation differences 0 0
At end of the year 130,864 143,712
Present value of defined benefit obligation | Foreign    
Defined Benefit Plan, Change in Benefit Liability [Roll Forward]    
At beginning of the year 301,078 247,725
Current service cost 12,281 11,233
Interest cost 9,170 9,427
Remeasurement of defined benefit pension plans    
From changes in demographic assumptions 37 197
From changes in financial assumptions (3,952) 11,387
Experience adjustments 7,006 (4,628)
Past service cost (2,731) (67)
Settlement (57,537)  
Benefits paid (17,053) (12,939)
Contributions by the employees 5,053 4,610
Effect of business combinations and disposals (95)  
Foreign currency translation differences 366 34,132
At end of the year ¥ 253,624 ¥ 301,078