Earnings Per Share - Computation of Earnings (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Income from continuing operations	$ 100.6	$ 96.1	$ 108.4
Gain from discontinued operations and disposal, net of tax	0.0	0.1	0.1
Net income	$ 100.6	$ 96.2	$ 108.5
Weighted average shares outstanding - basic (shares)	60.8	60.3	60.2
Dilutive effect of common stock equivalents (shares)	1.1	1.4	1.4
Weighted average shares outstanding - Diluted (shares)	61.9	61.7	61.6
Basic earnings per share:
Earnings from continuing operations (usd per share)	$ 1.65	$ 1.59	$ 1.80
Earnings from discontinued operations and disposal, net of tax (usd per share)	0	0.00	0.00
Net earnings per share (usd per share)	1.65	1.59	1.80
Diluted earnings per share:
Earnings from continuing operations (usd per share)	1.63	1.56	1.76
Earnings from discontinued operations and disposal, net of tax (usd per share)	0	0.00	0.00
Net earnings per share (usd per share)	$ 1.63	$ 1.56	$ 1.76