DefinedBenefitPlanChangeInDiscountRate

No definition available.

Name:	evrg_DefinedBenefitPlanChangeInDiscountRate
Namespace Prefix:	evrg_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

SegregatedAssetsForNonQualifiedBenefitPlans

+ References

No definition available.

+ Details

Name:	evrg_SegregatedAssetsForNonQualifiedBenefitPlans
Namespace Prefix:	evrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The unfunded accumulated benefit obligation related to non-qualified benefit plans.

+ References

No definition available.

+ Details

Name:	evrg_UnfundedAccumulatedBenefitObligationForNonQualifiedPlans
Namespace Prefix:	evrg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of contribution expected to be received by defined benefit plan from employer in next fiscal year following current fiscal year.

+ References

+ Details

Name:	us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of gain (loss) recognized in net periodic benefit (cost) credit from irrevocable action relieving primary responsibility for benefit obligation and eliminating risk related to obligation and assets used to effect settlement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (h)(7)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 45
-Paragraph 3A
-URI http://asc.fasb.org/extlink&oid=109237824&loc=SL108413299-114919

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (a)(7)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e2709-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlements1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The proportionate share of interest (percent) in a jointly owned utility plant.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 360
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 10.C)
-URI http://asc.fasb.org/extlink&oid=115995737&loc=d3e659983-123033

+ Details

Name:	us-gaap_JointlyOwnedUtilityPlantProportionateOwnershipShare
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RetirementPlanTypeAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=evrg_EvergyKansasCentralIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=evrg_EvergyMetroIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_JointlyOwnedUtilityPlantAxis=us-gaap_JointlyOwnedNuclearPowerPlantMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=evrg_EvergyKansasSouthIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

PENSION PLANS AND POST-RETIREMENT BENEFITS - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) Rate	Dec. 31, 2019 USD ($)	Dec. 31, 2020	Dec. 31, 2020 USD ($)
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Settlement and special termination benefits	$ 11.2	$ 15.6
Non-qualified benefit obligations		49.4		$ 52.1
Funded by trusts containing assets		$ 45.5		46.3
Contributions to plans in next year				131.6
Defined benefit plan basis point change in discount rate	70	70
Post-Retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Settlement and special termination benefits	$ 0.0	$ 0.0
Contributions to plans in next year				4.1
Evergy Kansas Central \| Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Settlement and special termination benefits	$ 0.0	0.0
Non-qualified benefit obligations		26.0		27.0
Funded by trusts containing assets		$ 31.7		32.7
Contributions to plans in next year				41.2
Defined benefit plan basis point change in discount rate	70	70
Evergy Kansas Central \| Post-Retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Settlement and special termination benefits	$ 0.0	$ 0.0
Contributions to plans in next year				0.6
Evergy Metro \| Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Settlement and special termination benefits	$ 14.3	$ 23.0
Contributions to plans in next year				90.4
Defined benefit plan basis point change in discount rate	70	70
Evergy Metro \| Post-Retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Settlement and special termination benefits	$ 0.0	$ 0.0
Contributions to plans in next year				$ 3.5
Wolf Creek
Defined Benefit Plan Disclosure [Line Items]
Jointly owned utility plant, proportionate ownership share	94.00%		94.00%
Wolf Creek \| Evergy Kansas South Inc
Defined Benefit Plan Disclosure [Line Items]
Jointly owned utility plant, proportionate ownership share			47.00%
Wolf Creek \| Evergy Kansas Central
Defined Benefit Plan Disclosure [Line Items]
Jointly owned utility plant, proportionate ownership share \| Rate	47.00%
Wolf Creek \| Evergy Metro
Defined Benefit Plan Disclosure [Line Items]
Jointly owned utility plant, proportionate ownership share	47.00%		47.00%