Cash and Cash Equivalents (Excluding Overdrafts) - Summary of Cash and Cash Equivalents (Detail) - GBP (£) £ in Millions	Dec. 31, 2022	Dec. 31, 2021
Cash and cash equivalents [line items]
Cash at bank and in hand	£ 269	£ 660
Short-term bank deposits	289	277
Total	£ 558	£ 937

A classification of cash equivalents representing short-term deposits. [Refer: Cash equivalents]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 7
-IssueDate 2022-03-24
-Paragraph 45
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2022-en-r&anchor=para_45&doctype=Standard
-URIDate 2022-03-24

Name:	ifrs-full_ShorttermDepositsClassifiedAsCashEquivalents
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant