v3.26.1
Employee benefits - Summary of Fair Value of Plan Assets Foreign Defined Benefit Plans (Detail) - Foreign Defined Benefit Plan [Member] - JPY (¥)
¥ in Millions
Mar. 31, 2026
Mar. 31, 2025
Disclosure of fair value of plan assets [line items]    
Cash and cash equivalents ¥ 4,695 ¥ 4,599
Equity securities [1] 119 101
Fixed income securities contributed to fair value of plan assets [Abstract]    
Government bonds [2] 1,070 1,207
Corporate bonds [3] 194 175
Asset-backed securities 196 43
Insurance contracts [4] 24,125 23,057
Commingled funds [5] 45,909 16,929
Real estate and other 4,953 3,537
Total 81,261 49,648
Quoted Market Prices in Active Market [Member]    
Disclosure of fair value of plan assets [line items]    
Cash and cash equivalents 4,695 4,599
Equity securities [1] 59 101
Fixed income securities contributed to fair value of plan assets [Abstract]    
Government bonds [2] 0  
Corporate bonds [3] 0  
Asset-backed securities 0  
Insurance contracts [4] 0 334
Commingled funds [5] 0  
Real estate and other 13  
Total 4,767 5,034
Unquoted Market Prices in Active Market [Member]    
Disclosure of fair value of plan assets [line items]    
Cash and cash equivalents 0  
Equity securities [1] 60  
Fixed income securities contributed to fair value of plan assets [Abstract]    
Government bonds [2] 1,070 1,207
Corporate bonds [3] 194 175
Asset-backed securities 196 43
Insurance contracts [4] 24,125 22,723
Commingled funds [5] 45,909 16,929
Real estate and other 4,940 3,537
Total ¥ 76,494 ¥ 44,614
[1] Represents primarily foreign equity securities.
[2] Includes primarily foreign government debt securities.
[3] Includes primarily foreign corporate debt securities.
[4] Represents annuity contracts with or without profit sharing and bulk insurance contracts.
[5] Commingled funds represent pooled institutional investments, including primarily investment trusts.