v3.26.1
Employee Benefits - Fair Value of Japanese and Foreign Pension Plan Assets By Asset Category (Detail) - JPY (¥)
¥ in Millions
Mar. 31, 2026
Mar. 31, 2025
Japanese plans [member]    
Disclosure of fair value of plan assets [line items]    
Cash and cash equivalents ¥ 13,585 ¥ 22,760
General accounts 39,574 39,871
Separate accounts 34,851 29,531
Insurance Contracts  
Other (6,961) (10,367)
Total 1,251,679 1,199,267
Japanese plans [member] | Real estate funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds 713 209
Japanese plans [member] | Private equity funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds
Japanese plans [member] | Hedge funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds 135,314 120,414
Japanese plans [member] | Commingled and other mutual funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds 154,342 159,255
Japanese plans [member] | Japan [member]    
Disclosure of fair value of plan assets [line items]    
Equity securities 21,501 22,005
Debt securities 44,213 49,254
Japanese plans [member] | United States [member]    
Disclosure of fair value of plan assets [line items]    
Equity securities 207,710 200,605
Debt securities 166,213 169,413
Japanese plans [member] | Other [member]    
Disclosure of fair value of plan assets [line items]    
Equity securities 177,791 145,331
Debt securities 262,833 250,986
Japanese plans [member] | Quoted, Market price in active market [member]    
Disclosure of fair value of plan assets [line items]    
Cash and cash equivalents 13,585 22,760
General accounts
Separate accounts
Insurance Contracts  
Other (140) 2
Total 707,841 721,468
Japanese plans [member] | Quoted, Market price in active market [member] | Real estate funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds
Japanese plans [member] | Quoted, Market price in active market [member] | Private equity funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds
Japanese plans [member] | Quoted, Market price in active market [member] | Hedge funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds
Japanese plans [member] | Quoted, Market price in active market [member] | Commingled and other mutual funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds 1,524 1,038
Japanese plans [member] | Quoted, Market price in active market [member] | Japan [member]    
Disclosure of fair value of plan assets [line items]    
Equity securities 21,501 22,005
Debt securities 42,351 47,992
Japanese plans [member] | Quoted, Market price in active market [member] | United States [member]    
Disclosure of fair value of plan assets [line items]    
Equity securities 207,710 200,605
Debt securities 132,985 145,869
Japanese plans [member] | Quoted, Market price in active market [member] | Other [member]    
Disclosure of fair value of plan assets [line items]    
Equity securities 177,745 145,261
Debt securities 110,580 135,936
Japanese plans [member] | Unquoted, Market price in active market [member]    
Disclosure of fair value of plan assets [line items]    
Cash and cash equivalents
General accounts 39,574 39,871
Separate accounts 34,851 29,531
Insurance Contracts  
Other (6,821) (10,369)
Total 543,838 477,799
Japanese plans [member] | Unquoted, Market price in active market [member] | Real estate funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds 713 209
Japanese plans [member] | Unquoted, Market price in active market [member] | Private equity funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds
Japanese plans [member] | Unquoted, Market price in active market [member] | Hedge funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds 135,314 120,414
Japanese plans [member] | Unquoted, Market price in active market [member] | Commingled and other mutual funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds 152,818 158,217
Japanese plans [member] | Unquoted, Market price in active market [member] | Japan [member]    
Disclosure of fair value of plan assets [line items]    
Equity securities
Debt securities 1,862 1,262
Japanese plans [member] | Unquoted, Market price in active market [member] | United States [member]    
Disclosure of fair value of plan assets [line items]    
Equity securities
Debt securities 33,228 23,544
Japanese plans [member] | Unquoted, Market price in active market [member] | Other [member]    
Disclosure of fair value of plan assets [line items]    
Equity securities 46 70
Debt securities 152,253 115,050
Foreign plans [member]    
Disclosure of fair value of plan assets [line items]    
Cash and cash equivalents 13,491 8,124
General accounts
Separate accounts
Insurance Contracts 127,441  
Other 66,362 42,109
Total 1,046,282 958,328
Foreign plans [member] | Real estate funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds 87,445 70,336
Foreign plans [member] | Private equity funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds 144,927 154,824
Foreign plans [member] | Hedge funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds 1,586 26,400
Foreign plans [member] | Commingled and other mutual funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds 348,676 459,546
Foreign plans [member] | Japan [member]    
Disclosure of fair value of plan assets [line items]    
Equity securities 683 546
Debt securities 1,508 1,055
Foreign plans [member] | United States [member]    
Disclosure of fair value of plan assets [line items]    
Equity securities 12,903 10,687
Debt securities 216,100 163,424
Foreign plans [member] | Other [member]    
Disclosure of fair value of plan assets [line items]    
Equity securities 9,755 6,733
Debt securities 15,405 14,544
Foreign plans [member] | Quoted, Market price in active market [member]    
Disclosure of fair value of plan assets [line items]    
Cash and cash equivalents 13,491 8,124
General accounts
Separate accounts
Insurance Contracts  
Other 381 382
Total 34,932 24,424
Foreign plans [member] | Quoted, Market price in active market [member] | Real estate funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds
Foreign plans [member] | Quoted, Market price in active market [member] | Private equity funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds
Foreign plans [member] | Quoted, Market price in active market [member] | Hedge funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds
Foreign plans [member] | Quoted, Market price in active market [member] | Commingled and other mutual funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds
Foreign plans [member] | Quoted, Market price in active market [member] | Japan [member]    
Disclosure of fair value of plan assets [line items]    
Equity securities 683 546
Debt securities
Foreign plans [member] | Quoted, Market price in active market [member] | United States [member]    
Disclosure of fair value of plan assets [line items]    
Equity securities 12,903 10,687
Debt securities
Foreign plans [member] | Quoted, Market price in active market [member] | Other [member]    
Disclosure of fair value of plan assets [line items]    
Equity securities 7,474 4,685
Debt securities
Foreign plans [member] | Unquoted, Market price in active market [member]    
Disclosure of fair value of plan assets [line items]    
Cash and cash equivalents
General accounts
Separate accounts
Insurance Contracts 127,441  
Other 65,981 41,727
Total 1,011,350 933,904
Foreign plans [member] | Unquoted, Market price in active market [member] | Real estate funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds 87,445 70,336
Foreign plans [member] | Unquoted, Market price in active market [member] | Private equity funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds 144,927 154,824
Foreign plans [member] | Unquoted, Market price in active market [member] | Hedge funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds 1,586 26,400
Foreign plans [member] | Unquoted, Market price in active market [member] | Commingled and other mutual funds [member]    
Disclosure of fair value of plan assets [line items]    
Pooled funds 348,676 459,546
Foreign plans [member] | Unquoted, Market price in active market [member] | Japan [member]    
Disclosure of fair value of plan assets [line items]    
Equity securities
Debt securities 1,508 1,055
Foreign plans [member] | Unquoted, Market price in active market [member] | United States [member]    
Disclosure of fair value of plan assets [line items]    
Equity securities
Debt securities 216,100 163,424
Foreign plans [member] | Unquoted, Market price in active market [member] | Other [member]    
Disclosure of fair value of plan assets [line items]    
Equity securities 2,281 2,048
Debt securities ¥ 15,405 ¥ 14,544