Schedule I - Short-Term Notes Payable to Related Parties (Details) - WEC Energy Group - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Notes to parent company financial statements
Notes payable to related parties	$ 459.6	$ 332.5
Integrys
Notes to parent company financial statements
Notes payable to related parties	257.0	115.0
WECC
Notes to parent company financial statements
Notes payable to related parties	109.2	106.5
WBS
Notes to parent company financial statements
Notes payable to related parties	91.8	111.0
Bluewater
Notes to parent company financial statements
Notes payable to related parties	$ 1.6	$ 0.0