Schedule I - Short-Term Notes Payable to Related Parties (Details) - WEC Energy Group - Related Party - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Notes to parent company financial statements
Notes payable to related parties	$ 580.9	$ 459.6
Integrys
Notes to parent company financial statements
Notes payable to related parties	327.0	257.0
WECC
Notes to parent company financial statements
Notes payable to related parties	111.1	109.2
WBS
Notes to parent company financial statements
Notes payable to related parties	90.4	91.8
Bluewater
Notes to parent company financial statements
Notes payable to related parties	$ 52.4	$ 1.6