RETIREMENT BENEFIT PLANS - Summary of Net Assets Recognised (Details) - GBP (£) £ in Millions |
Jun. 30, 2026 |
Dec. 31, 2025 |
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| Disclosure of net defined benefit liability (asset) [abstract] | ||
| Present value of defined benefit obligations | £ (6,974) | £ (7,127) |
| Fair value of scheme assets | 7,513 | 7,629 |
| Net defined benefit assets | £ 539 | £ 502 |
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- Definition The present value, without deducting any plan assets, of expected future payments required to settle the obligation resulting from employee service in the current and prior periods. [Refer: Plan assets, at fair value] Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- References No definition available.
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- Definition The amount of deficit or surplus in a defined benefit plan, adjusted for any effect of limiting a net defined benefit asset to the asset ceiling. [Refer: Defined benefit plans [domain]] Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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- Definition The fair value of defined benefit plan assets. Plan assets comprise assets held by a long-term employee benefit fund and qualifying insurance policies. [Refer: At fair value [member]] Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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