The option life of share options granted.

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Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with members defined in one or many axes of the table.

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The amount of expense from share-based payment transactions with employees. [Refer: Expense from share-based payment transactions]

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The difference, for modified share-based payment arrangements, between the fair value of the modified equity instrument and that of the original equity instrument, both estimated as at the date of the modification. [Refer: Types of share-based payment arrangements [domain]]

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The number of other equity instruments (ie other than share options) forfeited in a share-based payment arrangement.

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The number of share options granted in a share-based payment arrangement.

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Number of equity settled share based payment plans.

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Share-based Payments - Additional Information (Detail) £ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025 GBP (£) shares	Jun. 30, 2024 GBP (£) shares	Jun. 30, 2025 GBP (£) yr shares Plan	Jun. 30, 2024 GBP (£) shares
Disclosure of terms and conditions of share-based payment arrangement [line items]
Share-based payment expense \| £	£ 8.0	£ 0.7	£ 8.2	£ 1.3
Number of equity settled share-based payment plans \| Plan			6
2016 Share Option Scheme and 2020 Long-Term Incentive Plan [Member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of other equity instruments forfeited in share-based payment arrangement \| shares	14,380,933	0
Incremental fair value granted, modified share-based payment arrangements \| £	£ 13.5
Maximum [member] \| Employees [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Expected option life (years)			10
Maximum [member] \| Directors [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Expected option life (years)			10
Maximum [member] \| Consultants [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Expected option life (years)			10
Long-Term Incentive Plan [member]
Disclosure of terms and conditions of share-based payment arrangement [line items]
Number of share options granted in share-based payment arrangement \| shares			3,478,076,733	6,273,782