SHORT-TERM BORROWINGS AND SHORT-TERM BANK LINES OF CREDIT - Schedule of Short Term Debt (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Short-term Debt [Line Items]
Master Credit Facility	$ 2,500.0	$ 2,500.0
Available Borrowings	1,878.7	2,165.3
Evergy, Inc.
Short-term Debt [Line Items]
Master Credit Facility	700.0	450.0
Available Borrowings	$ 410.3	$ 249.3
Weighted Average Interest Rate on Short-Term Borrowings	0.21%	1.40%
Evergy Kansas Central
Short-term Debt [Line Items]
Master Credit Facility	$ 750.0	$ 1,000.0
Available Borrowings	$ 513.9	$ 933.0
Weighted Average Interest Rate on Short-Term Borrowings	0.19%	0.23%
Evergy Metro
Short-term Debt [Line Items]
Master Credit Facility	$ 350.0	$ 600.0
Available Borrowings	$ 350.0	$ 600.0
Weighted Average Interest Rate on Short-Term Borrowings	0.00%	0.00%
Evergy Missouri West
Short-term Debt [Line Items]
Master Credit Facility	$ 700.0	$ 450.0
Available Borrowings	$ 604.5	$ 383.0
Weighted Average Interest Rate on Short-Term Borrowings	0.17%	0.36%
Commercial Paper
Short-term Debt [Line Items]
Long-term line of credit	$ 620.5	$ 115.0
Commercial Paper \| Evergy, Inc.
Short-term Debt [Line Items]
Long-term line of credit	289.0
Commercial Paper \| Evergy Kansas Central
Short-term Debt [Line Items]
Long-term line of credit	236.0	50.0
Commercial Paper \| Evergy Metro
Short-term Debt [Line Items]
Long-term line of credit	0.0	0.0
Commercial Paper \| Evergy Missouri West
Short-term Debt [Line Items]
Long-term line of credit	95.5	65.0
Letters of Credit
Short-term Debt [Line Items]
Letters of Credit	0.8	19.7
Letters of Credit \| Evergy, Inc.
Short-term Debt [Line Items]
Letters of Credit	0.7	0.7
Letters of Credit \| Evergy Kansas Central
Short-term Debt [Line Items]
Letters of Credit	0.1	17.0
Letters of Credit \| Evergy Metro
Short-term Debt [Line Items]
Letters of Credit	0.0	0.0
Letters of Credit \| Evergy Missouri West
Short-term Debt [Line Items]
Letters of Credit	0.0	2.0
Cash Borrowings
Short-term Debt [Line Items]
Long-term line of credit	0.0	200.0
Cash Borrowings \| Evergy, Inc.
Short-term Debt [Line Items]
Long-term line of credit	0.0	200.0
Cash Borrowings \| Evergy Kansas Central
Short-term Debt [Line Items]
Long-term line of credit	0.0	0.0
Cash Borrowings \| Evergy Metro
Short-term Debt [Line Items]
Long-term line of credit	0.0	0.0
Cash Borrowings \| Evergy Missouri West
Short-term Debt [Line Items]
Long-term line of credit	$ 0.0	$ 0.0

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

No definition available.

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

+ Details

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- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

+ Details

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- Definition

The effective interest rate at the end of the reporting period.

+ References

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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- 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.

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