CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net reclassification adjustments for amounts recognized in net income as a component of net periodic benefit cost, tax expense	$ 0.5	$ 0.5	$ 1.5	$ 3.2
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, before Reclassification Adjustments, Tax	$ 0.0	$ 10.3	$ 0.0	$ 10.3