| Document and Entity Information | Apr. 20, 2021 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001711269 |
| Document Type | 8-K |
| Document Period End Date | Apr. 20, 2021 |
| Entity File Number | 001-38515 |
| Entity Registrant Name | Evergy, Inc. |
| Entity Tax Identification Number | 82-2733395 |
| Entity Incorporation State Country Code | MO |
| Entity Address, Address Line One | 1200 Main Street |
| Entity Address, City or Town | Kansas City |
| Entity Address, State or Province | MO |
| Entity Address, Postal Zip Code | 64105 |
| City Area Code | 816 |
| Local Phone Number | 556-2200 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Evergy, Inc. common stock |
| Trading Symbol | EVRG |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
