CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Pension and other postretirement plans adjustments:
Tax expense (benefit) on net unamortized gain (loss) incurred		$ (0.1)	$ (0.1)	$ (0.2)
Tax expense (benefit) on prior service cost incurred	$ (0.1)	$ (0.5)	$ (0.4)	$ (1.0)