COMMITMENTS AND CONTINGENCIES - Contractual Commitments (Details) $ in Millions	Dec. 31, 2020 USD ($)
Unrecorded Unconditional Purchase Obligations and Lease Commitments [Line Items]
2021	$ 509.0
2022	206.6
2023	217.1
2024	178.8
2025	168.3
After 2025	529.7
Total	1,809.5
Fuel
Unrecorded Unconditional Purchase Obligations and Lease Commitments [Line Items]
2021	311.2
2022	118.3
2023	134.6
2024	97.6
2025	88.4
After 2025	94.0
Total	844.1
Power
Unrecorded Unconditional Purchase Obligations and Lease Commitments [Line Items]
2021	62.4
2022	62.6
2023	63.2
2024	57.6
2025	58.0
After 2025	349.7
Total	653.5
Other
Unrecorded Unconditional Purchase Obligations and Lease Commitments [Line Items]
2021	135.4
2022	25.7
2023	19.3
2024	23.6
2025	21.9
After 2025	86.0
Total	311.9
Evergy Kansas Central
Unrecorded Unconditional Purchase Obligations and Lease Commitments [Line Items]
2021	217.3
2022	84.9
2023	94.6
2024	72.0
2025	66.1
After 2025	60.4
Total	595.3
Evergy Kansas Central \| Fuel
Unrecorded Unconditional Purchase Obligations and Lease Commitments [Line Items]
2021	149.3
2022	74.9
2023	85.5
2024	66.8
2025	62.3
After 2025	56.0
Total	494.8
Evergy Kansas Central \| Power
Unrecorded Unconditional Purchase Obligations and Lease Commitments [Line Items]
2021	1.4
2022	0.9
2023	0.9
2024	0.9
2025	0.9
After 2025	4.4
Total	9.4
Evergy Kansas Central \| Other
Unrecorded Unconditional Purchase Obligations and Lease Commitments [Line Items]
2021	66.6
2022	9.1
2023	8.2
2024	4.3
2025	2.9
After 2025	0.0
Total	91.1
Evergy Metro
Unrecorded Unconditional Purchase Obligations and Lease Commitments [Line Items]
2021	232.7
2022	89.1
2023	91.7
2024	75.9
2025	70.9
After 2025	315.5
Total	875.8
Evergy Metro \| Fuel
Unrecorded Unconditional Purchase Obligations and Lease Commitments [Line Items]
2021	142.8
2022	38.8
2023	46.3
2024	27.9
2025	23.2
After 2025	38.0
Total	317.0
Evergy Metro \| Power
Unrecorded Unconditional Purchase Obligations and Lease Commitments [Line Items]
2021	34.9
2022	35.1
2023	35.3
2024	29.2
2025	29.2
After 2025	196.1
Total	359.8
Evergy Metro \| Other
Unrecorded Unconditional Purchase Obligations and Lease Commitments [Line Items]
2021	55.0
2022	15.2
2023	10.1
2024	18.8
2025	18.5
After 2025	81.4
Total	$ 199.0

Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid in fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 440
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121559207&loc=d3e25336-109308

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- Definition

Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

+ Details

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- Definition

Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid in fourth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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- Definition

Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid in second fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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- Definition

Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid in third fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

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- Definition

Amount of the unrecorded obligation to transfer funds in the future for fixed or minimum amounts or quantities of goods or services at fixed or minimum prices (for example, as in take-or-pay contracts or throughput contracts).

+ References

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- Definition

Amount of fixed and determinable portion of unrecorded unconditional purchase obligation to be paid after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 440
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121559207&loc=d3e25336-109308

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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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