The amount of net operating loss carryforwards acquired in in the GMO acquisition.

No definition available.

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

- Definition

Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32559-109319

+ Details

Name:	us-gaap_OperatingLossCarryforwards
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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_OperatingLossCarryforwardsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The portion of the valuation allowance pertaining to the deferred tax asset representing potential future taxable deductions from net operating loss carryforwards for which it is more likely than not that a tax benefit will not be realized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32537-109319

+ Details

Name:	us-gaap_OperatingLossCarryforwardsValuationAllowance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of the tax credit carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

+ References

+ Details

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

- Details

Name:	us-gaap_TaxCreditCarryforwardAxis=evrg_FederalAlternativeMinimumTaxCreditCarryforwardMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeTaxAuthorityAxis=us-gaap_InternalRevenueServiceIRSMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeTaxAuthorityAxis=us-gaap_StateAndLocalJurisdictionMember
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_TaxPeriodAxis=evrg_TaxYear2005Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TaxPeriodAxis=us-gaap_TaxYear2006Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TaxPeriodAxis=us-gaap_TaxYear2014Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TaxPeriodAxis=us-gaap_TaxYear2015Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TaxPeriodAxis=us-gaap_TaxYear2016Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TaxPeriodAxis=us-gaap_TaxYear2017Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

TAXES - Net Operating Loss Carryforwards (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Operating Loss Carryforwards [Line Items]
Deferred tax benefits	$ 42.2	$ 132.4
Operating loss carryforwards of federal income tax benefit	7.1
Tax credit carryforward, amount	379.6
Federal Alternative Minimum Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount		37.9
Internal Revenue Service (IRS)
Operating Loss Carryforwards [Line Items]
Tax benefits related to NOLs	7.1
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Deferred tax benefits	8.8	31.0
Operating loss carryforwards of federal income tax benefit	7.1
Evergy Kansas Central
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	176.5
Evergy Kansas Central \| Federal Alternative Minimum Tax Credit Carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount		13.4
Evergy Kansas Central \| Internal Revenue Service (IRS)
Operating Loss Carryforwards [Line Items]
Deferred tax benefits		12.3
Evergy Kansas Central \| State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Deferred tax benefits		10.8
Evergy Metro
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	195.9
Evergy Metro \| Internal Revenue Service (IRS)
Operating Loss Carryforwards [Line Items]
Deferred tax benefits		56.2
Evergy Metro \| State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Deferred tax benefits	0.2	$ 5.7
2005
Operating Loss Carryforwards [Line Items]
Deferred tax benefits	10.2
Tax credit carryforward, amount	0.1
2005 \| Evergy Kansas Central
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	0.0
2005 \| Evergy Metro
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	0.0
2006
Operating Loss Carryforwards [Line Items]
Deferred tax benefits	32.0
Tax credit carryforward, amount	0.1
2006 \| Evergy Kansas Central
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	0.0
2006 \| Evergy Metro
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	0.0
2014
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	24.1
2014 \| Evergy Kansas Central
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	10.7
2014 \| Evergy Metro
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	13.0
2015
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	24.7
2015 \| Evergy Kansas Central
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	10.9
2015 \| Evergy Metro
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	13.2
2016
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	27.1
2016 \| Evergy Kansas Central
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	11.0
2016 \| Evergy Metro
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	12.4
2017
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	43.9
2017 \| Evergy Kansas Central
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	35.1
2017 \| Evergy Metro
Operating Loss Carryforwards [Line Items]
Tax credit carryforward, amount	$ 8.2