Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Numerator:
Net income	$ 155.9	$ 143.1	$ 151.3
Denominator:
Denominator for basic earnings per share — weighted average shares	35.4	35.4	35.0
Effect of dilutive securities:
Equity compensation plans	0.5	0.6	0.4
Denominator for diluted earnings per share — adjusted weighted average and assumed conversion	35.9	36.0	35.4
Basic earnings per share (in dollars per share)	$ 4.41	$ 4.04	$ 4.33
Diluted earnings per share (in dollars per share)	$ 4.35	$ 3.98	$ 4.27
Income from continuing operations	$ 155.9	$ 143.1	$ 150.2
Income (Loss) from Continuing Operations, Per Basic Share	$ 4.41	$ 4.04	$ 4.30
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax, Per Basic Share	$ 0	$ 0	$ 0.03
Total Discontinued Operations, Net of Taxes	$ 0.0	$ 0.0	$ 1.1
Income (Loss) from Continuing Operations, Per Diluted Share	$ 4.35	$ 3.98	$ 4.24
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax, Per Diluted Share	$ 0	$ 0	$ 0.03