| Cover Page | May 03, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | May 3, 2021 |
| Entity File Number | 001-09057 |
| Entity Registrant Name | WEC ENERGY GROUP, INC. |
| Entity Tax Identification Number | 39-1391525 |
| Entity Incorporation, State or Country Code | WI |
| Entity Address, Address Line One | 231 West Michigan Street |
| Entity Address, Address Line Two | P.O. Box 1331 |
| Entity Address, City or Town | Milwaukee |
| Entity Address, State or Province | WI |
| Entity Address, Postal Zip Code | 53201 |
| City Area Code | 414 |
| Local Phone Number | 221-2345 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $.01 Par Value |
| Trading Symbol | WEC |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000783325 |
| Amendment Flag | false |
