Stockholders' Equity - Reclassifications from Accumulated Other Comprehensive Loss (Details) - Amount Reclassified from Accumulated Other Comprehensive Loss - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	$ (0.7)	$ (1.5)	$ (1.5)	$ (3.0)
Reclassification from AOCI, Current Period, Tax	(0.2)	(0.5)	(0.5)	(1.0)
Total reclassifications for the period, net of tax	(0.5)	(1.0)	(1.0)	(2.0)
Other (income) expense, net
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Defined Benefit Plan, Actuarial Gain (Loss)			0.0	0.1
Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss)
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, before Tax	$ (0.7)	$ (1.5)	$ (1.5)	$ (3.1)