Earnings Per Share - Reconciliation of Net Income (Loss) to Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Income from continuing operations	$ 12.5	$ 7.5	$ 31.2	$ 27.3
Gain from discontinued operations and disposal, net of tax	0.0	1.0	0.0	3.9
Net income	$ 12.5	$ 8.5	$ 31.2	$ 31.2
Weighted average shares outstanding - Basic (shares)	59.8	59.8	59.7	60.7
Dilutive effect of common stock equivalents (shares)	0.8	0.8	0.7	0.8
Weighted average shares outstanding - Diluted (shares)	60.6	60.6	60.4	61.5
Basic earnings per share:
Earnings from continuing operations (usd per share)	$ 0.21	$ 0.12	$ 0.52	$ 0.45
Earnings from discontinued operations and disposal, net of tax (usd per share)	0.00	0.02	0.00	0.06
Net earnings per share (usd per share)	0.21	0.14	0.52	0.51
Diluted earnings per share:
Earnings from continuing operations (usd per share)	0.21	0.12	0.52	0.45
Earnings from discontinued operations and disposal, net of tax (usd per share)	0.00	0.02	0.00	0.06
Net earnings per share (usd per share)	$ 0.21	$ 0.14	$ 0.52	$ 0.51