Earnings Per Share - Reconciliation of Net Income to Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share [Abstract]
Income from continuing operations	$ 12.9	$ 7.2
Gain from discontinued operations and disposal, net of tax	0.0	0.1
Net income	$ 12.9	$ 7.3
Weighted average shares outstanding - Basic (shares)	59.8	59.6
Dilutive effect of common stock equivalents (shares)	1.0	0.7
Weighted average shares outstanding - Diluted (shares)	60.8	60.3
Basic earnings per share:
Earnings from continuing operations (usd per share)	$ 0.22	$ 0.12
Earnings from discontinued operations and disposal, net of tax (usd per share)	0.00	0.00
Net earnings per share (usd per share)	0.22	0.12
Diluted earnings per share:
Earnings from continuing operations (usd per share)	0.21	0.12
Earnings from discontinued operations and disposal, net of tax (usd per share)	0.00	0.00
Net earnings per share (usd per share)	$ 0.21	$ 0.12