Pension and Postretirement Benefits - Components of Net Periodic Benefit (Income) Expense (Details) $ in Millions	1 Months Ended		3 Months Ended
	Mar. 31, 2024 USD ($) retiree	Mar. 31, 2023 USD ($) retiree	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost			$ 0.3	$ 0.3
Interest cost			47.9	58.5
Expected return on plan assets			(56.2)	(69.4)
Amortization of prior service benefit			(1.2)	(1.2)
Recognized net actuarial loss (gain)			23.6	22.1
Settlement losses			132.3	183.2
Net periodic pension expense (income)			146.7	193.5
Pension Plans | U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost			0.0	0.0
Interest cost			31.0	40.8
Expected return on plan assets			(34.4)	(48.6)
Amortization of prior service benefit			(0.6)	(0.6)
Recognized net actuarial loss (gain)			18.4	19.9
Settlement losses			132.3	183.2
Net periodic pension expense (income)			146.7	194.7
Group annuity contract to transfer projected benefit obligations, purchase amount	$ 195.0	$ 265.0
Group annuity contract to transfer projected benefit obligations, number of retirees | retiree	3,800	8,650
Pension Plans | International Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost			0.3	0.3
Interest cost			16.9	17.7
Expected return on plan assets			(21.8)	(20.8)
Amortization of prior service benefit			(0.6)	(0.6)
Recognized net actuarial loss (gain)			5.2	2.2
Settlement losses			0.0	0.0
Net periodic pension expense (income)			0.0	(1.2)
Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost			0.1	0.0
Interest cost			0.6	0.8
Expected return on plan assets			0.0	(0.1)
Amortization of prior service benefit			0.0	(0.3)
Recognized net actuarial loss (gain)			(0.8)	(0.7)
Net periodic pension expense (income)			$ (0.1)	$ (0.3)