LIABILITIES ARISING FROM NON-PARTICIPATING INVESTMENT CONTRACTS - Narrative (Details) - GBP (£) £ in Millions	Dec. 31, 2022	Dec. 31, 2021
LIABILITIES ARISING FROM NON-PARTICIPATING INVESTMENT CONTRACTS (Details) - Narrative [Line Items]
Contracts held with reinsurers	£ 616	£ 759
Non participating life insurance policy
LIABILITIES ARISING FROM NON-PARTICIPATING INVESTMENT CONTRACTS (Details) - Narrative [Line Items]
Contracts held with reinsurers	£ 2	£ 3

The amount of a cedant’s net contractual rights under a reinsurance contract.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2023-01-01
-Name IFRS
-Number 4
-IssueDate 2022-03-24
-Paragraph 37
-Subparagraph e
-URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=4&code=ifrs-tx-2022-en-b&anchor=para_37_e&doctype=Standard&book=b
-URIDate 2022-03-24

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