The amount of decrease in the fair value measurement of liabilities due to a change in one or more unobservable inputs to reflect reasonably possible alternative assumptions.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 13
-IssueDate 2017-01-01
-Paragraph 93
-Subparagraph h
-Clause ii
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=13&date=2017-03-01&anchor=para_93_h_ii&doctype=Standard
-URIDate 2017-03-09

+ Details

Name:	ifrs-full_DecreaseInFairValueMeasurementDueToChangeInOneOrMoreUnobservableInputsToReflectReasonablyPossibleAlternativeAssumptionsLiabilities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

+ References

No definition available.

+ Details

Name:	ifrs-full_DisclosureOfFairValueMeasurementOfLiabilitiesLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The fair value of financial liabilities. [Refer: At fair value [member]; Financial liabilities]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2017-01-01
-Paragraph 25
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2017-03-01&anchor=para_25&doctype=Standard
-URIDate 2017-03-09

+ Details

Name:	ifrs-full_FinancialLiabilitiesAtFairValue
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of increase in the fair value measurement of liabilities due to a change in one or more unobservable inputs to reflect reasonably possible alternative assumptions.

+ References

+ Details

Name:	ifrs-full_IncreaseInFairValueMeasurementDueToChangeInOneOrMoreUnobservableInputsToReflectReasonablyPossibleAlternativeAssumptionsLiabilities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the percentage of fair value liabilities hierarchy to total financial liabilities.

+ References

No definition available.

+ Details

Name:	rbs_PercentageOfFairValueLiabilitiesHierarchyToTotalFinancialLiabilities
Namespace Prefix:	rbs_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	ifrs-full_MeasurementAxis=ifrs-full_RecurringFairValueMeasurementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfFinancialLiabilitiesAxis=rbs_IfrsDepositsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfFinancialLiabilitiesAxis=rbs_DebtSecuritiesInIssueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfFinancialLiabilitiesAxis=rbs_IfrsShortPositionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfFinancialLiabilitiesAxis=ifrs-full_DerivativesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_ClassesOfFinancialLiabilitiesAxis=rbs_SubordinatedFinancialLiabilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_LevelsOfFairValueHierarchyAxis=ifrs-full_Level1OfFairValueHierarchyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_LevelsOfFairValueHierarchyAxis=ifrs-full_Level2OfFairValueHierarchyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_LevelsOfFairValueHierarchyAxis=ifrs-full_Level3OfFairValueHierarchyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Financial Instruments: carried at fair value - valuation hierarchy of Liabilities (Details) - Recurring - GBP (£) £ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Fair value of liabilities
Liabilities	£ 245,200
Proportion (as a percent)	100.00%	100.00%
Sensitivity favourable	£ 120	£ 170
Sensitivity unfavourable	(120)	(170)
Deposits
Fair value of liabilities
Liabilities	61,800	53,200
Sensitivity favourable	30	20
Sensitivity unfavourable	(30)	(20)
Debt securities in issue
Fair value of liabilities
Liabilities	3,800	4,500
Sensitivity favourable		10
Sensitivity unfavourable		(10)
Short positions
Fair value of liabilities
Liabilities	35,000	28,500
Derivatives
Fair value of liabilities
Liabilities	143,700	154,600
Sensitivity favourable	90	140
Sensitivity unfavourable	(90)	(140)
Subordinated liabilities
Fair value of liabilities
Liabilities	900	900
Level 1
Fair value of liabilities
Liabilities	£ 29,600	£ 23,700
Proportion (as a percent)	12.10%	9.80%
Level 1 \| Short positions
Fair value of liabilities
Liabilities	£ 29,600	£ 23,700
Level 2
Fair value of liabilities
Liabilities	£ 213,600	£ 215,800
Proportion (as a percent)	87.10%	89.30%
Level 2 \| Deposits
Fair value of liabilities
Liabilities	£ 61,500	£ 53,000
Level 2 \| Debt securities in issue
Fair value of liabilities
Liabilities	3,500	4,200
Level 2 \| Short positions
Fair value of liabilities
Liabilities	5,400	4,800
Level 2 \| Derivatives
Fair value of liabilities
Liabilities	142,300	152,900
Level 2 \| Subordinated liabilities
Fair value of liabilities
Liabilities	900	900
Level 3
Fair value of liabilities
Liabilities	£ 2,030	£ 2,187	£ 2,505	£ 2,997
Proportion (as a percent)	0.80%	0.90%
Level 3 \| Deposits
Fair value of liabilities
Liabilities	£ 300	£ 200
Level 3 \| Debt securities in issue
Fair value of liabilities
Liabilities	300	300
Level 3 \| Derivatives
Fair value of liabilities
Liabilities	£ 1,400	£ 1,700