Other Current Assets (Schedule of Other Current Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Prepaid expenses	$ 13.9	$ 18.2
Fair value of derivative assets	0.6	3.4
Other	2.7	12.1
Total other current assets	$ 17.2	$ 33.7