Condensed Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Adjustment to pension and other benefit plans, tax impact	$ (1.1)	$ (1.0)	$ (3.6)	$ (2.9)
Unrealized gain or loss on investment, tax impact	0.1	0.0	(0.1)	0.0
Other Comprehensive Income, Unrealized Gain (loss) on derivatives arising during the period, tax	$ (0.2)	$ (0.2)	$ 0.8	$ (0.2)