Acquisition and Discontinued Operations (Summary of Results of Discontinued Operations) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Income tax expense (benefit)	$ 0.2	$ (0.1)	$ 0.5	$ (1.9)
Net (loss) gain on disposal of discontinued business	(0.2)	0.3	(0.6)	2.0
DLW and AFI [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Gain (loss) on disposal of discontinued business before income tax		0.2	(0.1)	0.1
Income tax expense (benefit)	0.2	(0.1)	0.5	(1.9)
Net (loss) gain on disposal of discontinued business	$ (0.2)	$ 0.3	$ (0.6)	$ 2.0