Pensions - History of defined benefit schemes (Details) - GBP (£) £ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pensions
Fair value of plan assets	£ 37,598	£ 57,787	£ 57,249	£ 51,925	£ 48,752
Present value of plan obligations	(27,601)	(46,808)	(48,864)	(44,115)	(39,607)
Net surplus	9,997	10,979	8,385	7,810	9,145
Actual return on plan assets	£ (19,285)	£ 1,667	£ 7,064	£ 4,930	£ (848)
Actual return on plan assets - %	(33.40%)	2.90%	13.60%	10.10%	(1.70%)
Plan liabilities
Pensions
Experience (losses)/gains	£ (2,137)	£ 237	£ 455	£ 279	£ (81)
Plan assets
Pensions
Experience (losses)/gains	(20,326)	872	6,027	3,556	(2,090)
Main Scheme
Pensions
Fair value of plan assets	34,016	52,021	51,323	46,555	43,806
Present value of plan obligations	(24,733)	(42,020)	(43,870)	(39,669)	(35,466)
Net surplus	9,283	10,001	7,453	6,886	8,340
Actual return on plan assets	£ (17,248)	£ 1,554	£ 6,422	£ 4,266	£ (768)
Actual return on plan assets - %	(33.20%)	3.00%	13.80%	9.70%	(1.70%)
Main Scheme \| Plan liabilities
Pensions
Experience (losses)/gains	£ (2,053)	£ 241	£ 427	£ 275	£ (122)
Main Scheme \| Plan assets
Pensions
Experience (losses)/gains	£ (18,180)	£ 841	£ 5,486	£ 3,021	£ (1,891)

The amount of other comprehensive income, before tax, resulting from actuarial gains (losses) arising from experience adjustments that result in remeasurements of the net defined benefit liability (asset). Experience adjustments deal with the effects of differences between the previous actuarial assumptions and what has actually occurred. [Refer: Other comprehensive income, before tax, gains (losses) on remeasurements of defined benefit plans] [Contrast: Decrease (increase) in net defined benefit liability (asset) resulting from actuarial gains (losses) arising from experience adjustments]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 19
-IssueDate 2022-03-24
-Paragraph 135
-Subparagraph b
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2022-en-r&anchor=para_135_b&doctype=Standard
-URIDate 2022-03-24

+ Details

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

- Definition

The present value, without deducting any plan assets, of expected future payments required to settle the obligation resulting from employee service in the current and prior periods. [Refer: Plan assets, at fair value]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 19
-IssueDate 2022-03-24
-Paragraph 57
-Subparagraph a
-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2022-en-r&anchor=para_57_a&doctype=Standard
-URIDate 2022-03-24

+ Details

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

- Definition

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

+ References

No definition available.

+ Details

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

- Definition

The fair value of defined benefit plan assets. Plan assets comprise assets held by a long-term employee benefit fund and qualifying insurance policies. [Refer: At fair value [member]]

+ References

+ Details

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

- Definition

The amount of other comprehensive income, before tax, resulting from the return on plan assets, excluding amounts included in interest expense (income) arising from defined benefit plans. The return on plan assets is interest, dividends and other revenue derived from the plan assets, together with realised and unrealised gains or losses on the plan assets, less any costs of managing plan assets and less any tax payable by the plan itself, other than tax included in the actuarial assumptions used to measure the present value of the defined benefit obligation. [Refer: Other comprehensive income; Defined benefit plans [member]; Plan assets [member]; Other comprehensive income, before tax, gains (losses) on remeasurements of defined benefit plans] [Contrast: Decrease (increase) in net defined benefit liability (asset) resulting from return on plan assets excluding interest income or expense]

+ References

+ Details

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

- Definition

The fair value of any plan assets, less the present value of the defined benefit obligation. [Refer: Plan assets [member]]

+ References

+ Details

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

- Definition

Percentage of actual return on plan assets.

+ References

No definition available.

+ Details

Name:	nwg_PercentageOfActualReturnOnPlanAssets
Namespace Prefix:	nwg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	ifrs-full_NetDefinedBenefitLiabilityAssetAxis=ifrs-full_PresentValueOfDefinedBenefitObligationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_NetDefinedBenefitLiabilityAssetAxis=ifrs-full_PlanAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_DefinedBenefitPlansAxis=nwg_MainSectionOfRoyalBankOfScotlandGroupPensionFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: