Goodwill and Other Intangible Assets (Amortization Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of Intangible Assets	$ 12.5	$ 10.6	$ 8.3
Finite-lived intangible assets, next twelve months	10.9
Finite-lived intangible assets, year two	8.3
Finite-lived intangible assets, year three	2.3
Finite-lived intangible assets, year four	0.7
Finite-lived intangible assets, year five	0.9
Total	$ 23.1