Taxation - Additional Information (Details) - GBP (£) £ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Major components of tax expense (income) [abstract]
Effective tax rate on (loss)/profit before tax	43.10%	33.10%	24.20%
Current year	£ (197.1)	£ 9.4	£ (131.0)
Remeasurement of UK deferred tax balances, recognized tax credit	£ 0.0	£ 0.0	£ 23.8

The amount of deferred tax expense or income relating to tax rate changes or the imposition of new taxes. [Refer: Deferred tax expense (income)]

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 12
-IssueDate 2023-01-01
-Paragraph 80
-Subparagraph d
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=12&code=ifrs-tx-2023-en-r&anchor=para_80_d&doctype=Standard
-URIDate 2023-03-23

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration