v3.26.1
Property, Plant and Equipment - Summary of Changes in the Carrying Amounts of the Right-of-Use Assets (Detail) - JPY (¥)
¥ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Disclosure Of Depreciation For The Right Of Use Assets [Line Items]    
Opening Balance ¥ 309,705 ¥ 323,011
Additions 87,064 75,239
Depreciation (77,367) (75,624)
Other (63) (12,921)
Ending balance 319,339 309,705
Land [member]    
Disclosure Of Depreciation For The Right Of Use Assets [Line Items]    
Opening Balance 86,637 91,186
Additions 8,500 5,689
Depreciation (6,988) (6,399)
Other 1,032 (3,839)
Ending balance 89,181 86,637
Buildings and structures [member]    
Disclosure Of Depreciation For The Right Of Use Assets [Line Items]    
Opening Balance 143,825 137,598
Additions 38,740 33,006
Depreciation (26,452) (19,110)
Other (366) (7,669)
Ending balance 155,747 143,825
Machinery and equipment [member]    
Disclosure Of Depreciation For The Right Of Use Assets [Line Items]    
Opening Balance 79,243 94,227
Additions 39,824 36,544
Depreciation (43,927) (50,115)
Other (729) (1,413)
Ending balance ¥ 74,411 ¥ 79,243