Schedule I - Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Notes to parent company financial statements
Cash (paid) received for income taxes, net		$ 9.3	$ 22.0
WEC Energy Group
Notes to parent company financial statements
Cash (paid) for interest	$ (89.6)	(68.8)	(44.4)
Cash (paid) received for income taxes, net	(62.9)	$ 242.9	$ 95.1
Short-term note payable settled through a non-cash capital contribution	$ 40.0