Lease arrangements - Summary of finance lease receivable (Details) - GBP (£) £ in Millions	Dec. 31, 2023	Dec. 31, 2022
Lease arrangements
Net finance lease receivable	£ 4	£ 5

The amount of current finance lease receivables. [Refer: Finance lease receivables]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 1
-IssueDate 2023-01-01
-Paragraph 55
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=1&code=ifrs-tx-2023-en-r&anchor=para_55&doctype=Standard
-URIDate 2023-03-23

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