Intangible assets - Summary of intangible assets and goodwill (Details) £ in Millions	12 Months Ended
Dec. 31, 2023 GBP (£)
Goodwill
Disclosure of detailed information about intangible assets
Decrease through classification as held for sale	£ 51
Impairment	42
Intangible assets
Disclosure of detailed information about intangible assets
Decrease through classification as held for sale	£ 31

The decrease in intangible assets other than goodwill resulting from classification as held for sale or inclusion in a disposal group classified as held for sale. [Refer: Disposal groups classified as held for sale [member]; Intangible assets other than goodwill]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 38
-IssueDate 2023-01-01
-Paragraph 118
-Subparagraph e
-Clause ii
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=38&code=ifrs-tx-2023-en-r&anchor=para_118_e_ii&doctype=Standard
-URIDate 2023-03-23

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- Definition

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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- Definition

The gains on subsequent increase in fair value less costs to sell (not in excess of recognised cumulative impairment loss) and losses on write-down to fair value less costs to sell for non-current assets or disposal groups held for sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 5
-IssueDate 2023-01-01
-Paragraph 41
-Subparagraph c
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=5&code=ifrs-tx-2023-en-r&anchor=para_41_c&doctype=Standard
-URIDate 2023-03-23

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