Employee Retirement Plans - Pension Plans (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Net pension income	$ 0.2	$ 0.4
Pension Plans
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Interest cost	(4.1)	(4.4)
Expected return on plan assets	4.5	5.0
Net periodic pension income	0.4	0.6
Amortization of actuarial loss	(0.2)	(0.2)
Net pension income	0.2	$ 0.4
Pension Plans | Non-qualified
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Benefit payments on non-qualified pension plans	0.1
Pension Plans | Qualified
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Contributions on qualified pension plans	$ 0.0