Pension Plans and Postretirement Benefits - Additional Details (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Retirement Benefits [Abstract]
Service cost	$ 2.9	$ 2.6	$ 5.9	$ 5.2
Net periodic benefit (income) cost, excluding service costs	$ (9.5)	$ (5.3)	$ (19.0)	$ (10.5)