Accounting Standard Changes (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Provision for income taxes	$ (7.8)			$ (8.0)	$ (26.9)	$ (25.8)
Income from continuing operations	16.4			$ 13.5	$ 57.0	$ 46.0
New Accounting Pronouncement, Early Adoption, Effect [Member] | Accounting Standards Update 2016-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Provision for income taxes	(0.4)	$ (0.7)	$ (0.2)
Income from continuing operations	$ 0.4	$ 0.7	$ 0.2