STATEMENTS OF CONSOLIDATED COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2025	Mar. 31, 2024	[2]
Statement of Comprehensive Income [Abstract]
Net income	[1]	$ 21.6	$ 18.2
Other comprehensive income (loss), net of tax - Note 8:
Defined benefit plans		0.1	(0.5)
Cash flow hedges		2.5	(1.6)
Other comprehensive income (loss), net of tax		2.6	(2.1)
Comprehensive income		$ 24.2	$ 16.1

[1] See Note 12 for supplemental cash flow information.

[2] Adjusted to reflect the retrospective change in inventory valuation methodology from LIFO to WAC. See Note 14 for further discussion.