GOODWILL (Details) - GBP (£) £ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
GOODWILL (Details) [Line Items]
Goodwill	£ 2,324	£ 2,310	£ 2,310
Scottish Widows [member]
GOODWILL (Details) [Line Items]
Goodwill	£ 1,836	£ 1,836
Percentage of entity goodwill	79.00%	79.00%
MBNA Limited [Member]
GOODWILL (Details) [Line Items]
Goodwill	£ 302	£ 302
Percentage of entity goodwill	13.00%	13.00%
Motor Finance [member]
GOODWILL (Details) [Line Items]
Goodwill	£ 170	£ 170
Percentage of entity goodwill	7.00%	7.00%

The amount of assets representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognised. [Refer: Business combinations [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant