Restructuring and Relocation Activities - Additional Information (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost And Reserve [Line Items]
Restructuring expected accrual to pay	$ 15.4
Restructuring expected accrual remaining to pay	$ 0.7
Program
Restructuring Cost And Reserve [Line Items]
Total estimated net cash cost		$ 120.0