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
Net loss arising from remeasurement during the period, tax	$ 0.6	$ 0.0	$ 0.6	$ 0.0
Amortization of prior service benefits, tax	(1.4)	(1.4)	(2.8)	(2.8)
Amortization of net actuarial loss, tax	3.8	1.8	6.2	4.2
Reclassification adjustment for curtailment loss included in net income, tax	$ 0.1	$ 0.0	$ 0.1	$ 0.0