STATEMENTS OF CONSOLIDATED COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 15.9	$ 8.1
Other comprehensive income (loss), net of tax - Note 8:
Defined benefit plans	0.7	0.9
Cash flow hedges	(1.8)	17.1
Other comprehensive (loss) income, net of tax	(1.1)	18.0
Comprehensive income	$ 14.8	$ 26.1