v3.26.1
Goodwill and Other Intangible Assets (Carrying Amount of Other Intangible Assets by Major Class) (Detail) - JPY (¥)
¥ in Millions
Mar. 31, 2026
Mar. 31, 2025
Intangible assets subject to amortization:    
Gross carrying amount ¥ 5,277,772 ¥ 4,974,424
Accumulated amortization 3,825,617 3,580,136
Net carrying amount 1,452,155 1,394,288
Intangible assets not subject to amortization:    
Total 1,475,018 1,402,515
Indefinite-lived trade names    
Intangible assets not subject to amortization:    
Other 14,050 0
Other    
Intangible assets not subject to amortization:    
Other 8,813 8,227
Software    
Intangible assets subject to amortization:    
Gross carrying amount 4,427,757 4,093,320
Accumulated amortization 3,342,584 3,081,494
Net carrying amount 1,085,173 1,011,826
Customer relationships    
Intangible assets subject to amortization:    
Gross carrying amount 623,399 632,016
Accumulated amortization 336,393 335,898
Net carrying amount 287,006 296,118
Core deposit intangibles    
Intangible assets subject to amortization:    
Gross carrying amount 132,465 138,203
Accumulated amortization 108,418 102,052
Net carrying amount 24,047 36,151
Indefinite-lived trade names    
Intangible assets subject to amortization:    
Gross carrying amount 61,729 87,183
Accumulated amortization 26,917 50,871
Net carrying amount 34,812 36,312
Other    
Intangible assets subject to amortization:    
Gross carrying amount 32,422 23,702
Accumulated amortization 11,305 9,821
Net carrying amount ¥ 21,117 ¥ 13,881