CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Statement of Partners' Capital [Abstract]
Tax benefit (expense) on net change in postretirement benefit plans	$ (1.5)	$ 1.7	$ (7.6)
Tax expense (benefit) on amortization of prior service benefit	(1.3)	(1.4)	(1.3)
Tax (benefit) on amortization of net actuarial loss	0.1		(0.5)
Tax expense (benefit) on recognition of plan settlement costs	0.2	0.0	0.0
Tax benefit (expense) on prior service credit from plan amendment	0.2		(1.9)
Tax benefit (expense) benefit on net actuarial loss arising during the period	(3.1)	0.3	(6.5)
Disclosure of reclassification adjustments to cumulative translation adjustment
Cumulative translation adjustment loss recognized on divestiture of businesses	$ (3.6)	$ 0.0	$ 0.0