Business Segment Information (Reconciliation of Assets from Segment to Consolidated) (Detail) - JPY (¥) ¥ in Billions |
12 Months Ended | ||||||||
|---|---|---|---|---|---|---|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
Mar. 31, 2024 |
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| Schedule Of Assets By Segment [Line Items] | |||||||||
| Fixed assets | [1],[2] | ¥ 2,019.6 | ¥ 1,931.4 | ¥ 1,864.6 | |||||
| U.S. GAAP adjustments | [3] | 542.0 | 555.6 | 582.2 | |||||
| Premises and equipment-net, Goodwill, Intangible assets, and right-of-use assets related to operating leases included in Other assets | ¥ 2,561.6 | ¥ 2,487.1 | ¥ 2,446.9 | ||||||
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