Other Current Assets (Schedule of Other Current Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Prepaid expenses	$ 16.5	$ 15.0
Fair value of derivative assets	1.1	2.4
Other	1.6	3.4
Total other current assets	$ 19.2	$ 20.8