CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Statement of Partners' Capital [Abstract]
Net change in postretirement benefit plans, net of tax impacts of $(1.2), $(1.5), and $1.7, respectively	$ (1.2)	$ (1.5)	$ 1.7
Amortization of prior service benefit, net of tax expense of $1.4, $1.3, and $1.4, respectively	(1.4)	(1.3)	(1.4)
Amortization of net actuarial loss, net of tax benefit of $(0.2), $0.1, and $0.0, respectively	(0.2)	0.1
Loss on plan settlement, net of tax benefit of $0.0, $0.2, and $0.0, respectively	0.0	0.2	0.0
Prior service (cost) benefit, net of tax benefit (expense) of $0.0, $0.2, and $0.0, respectively		0.2
Net actuarial gain (loss), net of tax (expense) benefit of $(2.8), $(3.1), and $0.3, respectively	(2.8)	(3.1)	0.3
Disclosure of reclassification adjustments to cumulative translation adjustment
Cumulative translation adjustment loss recognized on divestiture of businesses	$ 0.0	$ (3.6)	$ 0.0