Equity dividends - Ordinary dividends paid (Details) - GBP (£) £ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Equity dividends
Ordinary dividends paid	£ 1,059	£ 983	£ 920

The cash outflow for dividends paid to equity holders of the parent, classified as financing activities.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 7
-IssueDate 2023-01-01
-Paragraph 17
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2023-en-r&anchor=para_17&doctype=Standard
-URIDate 2023-03-23

Name:	ifrs-full_DividendsPaidToEquityHoldersOfParentClassifiedAsFinancingActivities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration