Cash Generated from Operations - Summary of Proceeds from Sale of Property, Plant and Equipment (Detail) - GBP (£) £ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021
Property, plant and equipment [abstract]
Net book amount	£ 9	£ 4
Profit/(loss) on sale of property, plant and equipment	5	(4)
Proceeds from sale of property, plant and equipment	£ 14

The decrease in property, plant and equipment resulting from disposals. [Refer: Property, plant and equipment]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 16
-IssueDate 2022-03-24
-Paragraph 73
-Subparagraph e
-Clause ii
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- Definition

The gains (losses) on disposals of property, plant and equipment. [Refer: Property, plant and equipment]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2022-03-24
-Paragraph 98
-Subparagraph c
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- Definition

The cash inflow from sales of property, plant and equipment, classified as investing activities. [Refer: Property, plant and equipment]

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 7
-IssueDate 2022-03-24
-Paragraph 16
-Subparagraph b
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=7&code=ifrs-tx-2022-en-r&anchor=para_16_b&doctype=Standard
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- References

No definition available.

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