Equity - Schedule of Components of Accumulated Other Comprehensive Income (Loss) (Parenthetical) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Equity [Abstract]
Derivative instrument fair market value, tax	$ (0.3)	$ (0.3)
Employee pension and postretirement benefit adjustments, tax	$ (14.9)	$ (19.0)