CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Statement of Comprehensive Income [Abstract]
Net income	$ 97.4	$ 78.7	$ 262.2	$ 197.7
Other comprehensive income:
Reclassification adjustment transferred to Net income from cash flow hedges	0.1	0.1	0.1	0.1
Pension and other postretirement benefit costs, net of tax	0.0	0.7	0.0	1.3
Total Comprehensive Income	$ 97.5	$ 79.5	$ 262.3	$ 199.1