Accumulated Other Comprehensive (Loss) Income - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017
Unrecognized Net Defined Benefit and Postretirement Plan Costs
Accumulated Other Comprehensive Income Loss [Line Items]
Reclassification adjustment from AOCI on unrecognized net defined benefit and postretirement plan costs, net gains	$ 0.4	$ 0.7
Reclassification adjustment from AOCI on unrecognized net defined benefit and postretirement plan costs, tax	0.1	0.2
Change in Fair Value of Derivatives Products
Accumulated Other Comprehensive Income Loss [Line Items]
Reclassification adjustment from AOCI on derivatives, net losses	0.4	10.7
Reclassification adjustment from AOCI on derivatives, tax benefit	$ 0.1	$ 2.2