Goodwill and Intangible Assets (Gross Carrying Amount, Accumulated Amortization and Net Carrying Amount of Intangible Assets) (Detail) - JPY (¥) ¥ in Millions |
Mar. 31, 2026 |
Mar. 31, 2025 |
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|---|---|---|---|---|
| Intangible Assets by Major Class [Line Items] | ||||
| Gross carrying amount | ¥ 157,640 | ¥ 143,254 | ||
| Gross carrying amount | 6,831 | 6,920 | ||
| Gross carrying amount | 164,471 | 150,173 | ||
| Accumulated amortization | 122,251 | 114,702 | ||
| Net carrying amount | 35,389 | 28,552 | ||
| Net carrying amount | 6,831 | 6,920 | ||
| Net carrying amount | 42,220 | 35,472 | ||
| Customer relationships | ||||
| Intangible Assets by Major Class [Line Items] | ||||
| Gross carrying amount | [1] | 150,652 | 135,756 | |
| Accumulated amortization | [1] | 117,197 | 109,570 | |
| Net carrying amount | [1] | 33,455 | 26,186 | |
| Other | ||||
| Intangible Assets by Major Class [Line Items] | ||||
| Gross carrying amount | 6,988 | 7,498 | ||
| Accumulated amortization | 5,054 | 5,131 | ||
| Net carrying amount | ¥ 1,934 | ¥ 2,366 | ||
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