Retirement benefits - Assumptions Used in Accounting for Pension Plan (Detail) - Pension |
12 Months Ended | ||||
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Mar. 31, 2026 |
Mar. 31, 2025 |
Mar. 31, 2024 |
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| Defined Benefit Plan Disclosure [Line Items] | |||||
| Discount rate - net periodic benefit cost | [1] | 7.70% | 7.20% | 7.70% | |
| Rate of increase in compensation levels of covered employees | 7.00% | 7.00% | 7.00% | ||
| Rate of return on plan assets | 6.50% | 6.50% | 6.50% | ||
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- Definition Weighted average rate for present value of future retirement benefits cash flows, used to determine net periodic benefit cost of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Weighted average rate of return on plan assets, reflecting average rate of earnings expected on existing plan assets and expected contributions, used to determine net periodic benefit cost of defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Weighted average rate of compensation increase used to determine net periodic benefit cost of defined benefit plan. Plan includes, but is not limited to, pay-related defined benefit plan. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Details
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