Other Comprehensive (Loss) Income - Amounts Reclassified from Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other expense - net	$ 16.2	$ 5.6	$ 1.8
Interest expense	41.0	44.8	44.3
Income before income taxes	(579.8)	(470.3)	(532.9)
Provision for income taxes	130.5	92.5	107.4
Total net of tax	(449.4)	(377.8)	(425.5)
Reclassification out of Accumulated Other Comprehensive Income | Retirement Benefits Adjustments
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes	10.3	2.9	2.8
Provision for income taxes	(2.4)	(0.1)	(0.9)
Total net of tax	7.9	2.8	1.9
Reclassification out of Accumulated Other Comprehensive Income | Amortization and settlement loss, net of curtailment gain
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other expense - net	1.8	2.9	2.9
Reclassification out of Accumulated Other Comprehensive Income | Settlement loss recognized
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other expense - net	10.5	0.0	(0.1)
Reclassification out of Accumulated Other Comprehensive Income | Curtailment gain recognized
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other expense - net	(2.0)	0.0	0.0
Reclassification out of Accumulated Other Comprehensive Income | Cumulative Unrealized Gain (Loss)  on Derivatives
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	3.3	6.0	6.3
Income before income taxes	3.3	6.0	6.3
Provision for income taxes	(0.8)	(1.4)	(1.4)
Total net of tax	$ 2.5	$ 4.6	$ 4.9