SUPPLEMENTAL CASH FLOW INFORMATION (Tables)

9 Months Ended

Sep. 30, 2018

Supplemental Cash Flow Information [Abstract]

Schedule of supplemental cash flow information

	Nine Months Ended September 30
(in millions)	2018			2017
Cash (paid) for interest, net of amount capitalized	$	(27.9	)	$	(27.8	)
Cash (paid) for income taxes, net	(13.4		)	(27.5		)
Significant noncash transactions:
Accounts payable related to construction costs	16.9			36.3
Accounts payable related to assets transferred from affiliates	2.7			—
Transfer of ownership in WPSI to another subsidiary of Integrys *	—			67.2
Transfer of net assets to UMERC *	—			21.1

* See Note 16, Related Parties, for more information on these transactions.