Income Taxes - Valuation Allowances (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Beginning of year	$ 128.1	$ 118.3	$ 100.7
Expiring tax credits	(0.7)	(0.4)	(0.3)
Acquisitions and dispositions	(0.8)	4.9	3.1
Changes in judgment about deferred tax assets(a)	8.8	(2.4)	5.3
Income from continuing operations	103.1	16.8	28.3
Other comprehensive income	89.5	(16.2)	3.9
Foreign currency exchange effects	(1.1)	(0.1)	(0.5)
End of year	141.5	128.1	118.3
Valuation Allowance of Deferred Tax Assets
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Income from continuing operations	7.4	8.1	10.0
Other comprehensive income	$ (0.2)	$ (0.3)	$ 0.0