Accumulated Other Comprehensive Income (Loss) - Reclassifications (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Reclassifications out of AOCI [Line Items]
Other income (expense) - net	$ (0.1)	$ (0.6)
Interest expense	85.3	55.3
Tax benefit (expense)	(44.2)	(11.8)
Net income (loss)	21.9	32.8
Reclassification out of Accumulated Other Comprehensive Income
Reclassifications out of AOCI [Line Items]
Interest expense	(21.2)	(14.3)
Total before tax	(21.6)	(15.0)
Tax benefit (expense)	5.3	3.7
Net income (loss)	(16.3)	(11.3)
Amortization of prior service costs | Reclassification out of Accumulated Other Comprehensive Income
Reclassifications out of AOCI [Line Items]
Other income (expense) - net	(0.1)	(0.1)
Amortization of actuarial gain/loss | Reclassification out of Accumulated Other Comprehensive Income
Reclassifications out of AOCI [Line Items]
Other income (expense) - net	$ (0.3)	$ (0.6)