Consolidated Statements of Income and Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Reclassification adjustments to cash flow hedges included in net income, net of tax of $0.5 million, $0.5 million, $1.6 million, and $1.6 million	$ 0.5	$ 0.5	$ 1.6	$ 1.6
Amortization of pension and postretirement plans actuarial loss and prior service cost, net of tax of $1.4 million, $0.7 million, $4.2 million, and $2.2 million	$ 1.4	$ 0.7	$ 4.2	$ 2.2