Acquisitions and Discontinued Operations - Components of Discontinued Operations (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Combination And Disposal Groups, Including Discontinued Operations, Disclosure [Abstract]
Net sales									$ 0.0	$ 0.0	$ 693.9
Cost of goods sold									0.0	0.0	424.0
Gross profit									0.0	0.0	269.9
Selling, general and administrative									(1.2)	7.4	237.8
Research and development									0.0	0.0	14.6
Operating income (loss)									1.2	(7.4)	17.5
Income (loss) from discontinued operations before income taxes									1.6	(7.6)	31.8
Income tax provision (benefit)									0.1	(1.6)	6.1
Income (loss) from discontinued operations, net of tax	$ 3.2	$ 0.0	$ (1.7)	$ 0.0	$ (5.1)	$ 1.0	$ (0.8)	$ (1.1)	$ 1.5	$ (6.0)	$ 25.7