CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Reclassification of net losses (gains) to net income, tax	$ 0.1	$ 0.0	$ 0.2	$ 0.9
Pension and other postretirement benefit adjustments arising during period, tax	0.4	0.0	0.4	(0.1)
Amortization of pension and other postretirement benefit costs included in net periodic benefit cost, tax	$ 0.6	$ 0.2	$ 1.1	$ 0.5