SECURITISATIONS AND COVERED BONDS (Details) - Securitisation programme [Member] - GBP (£) £ in Millions	Dec. 31, 2018	Dec. 31, 2017
SECURITISATIONS AND COVERED BONDS (Details) [Line Items]
Securitisation Notes At Fair Value Through Profit Or Loss	£ 53
Cash Deposits Held Restricted In Use To Securitisation And Covered Bonds	4,102	£ 3,507
Maximum exposure to loss from interests in structured entities	£ 88	£ 95

The amount that best represents the entity's maximum exposure to loss from its interests in structured entities. [Refer: Unconsolidated structured entities [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 12
-IssueDate 2018-01-01
-Paragraph 29
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=12&date=2018-03-01&anchor=para_29_c&doctype=Standard
-URIDate 2018-03-16

Name:	ifrs-full_MaximumExposureToLossFromInterestsInStructuredEntities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant