Other Noncurrent Liabilities - Other Noncurrent Liabilities (Detail) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Other Liabilities Disclosure [Abstract]
Operating lease liabilities	$ 23.1
Accrued litigation settlement	59.8	$ 17.0
Reserve for uncertain tax positions	20.2	19.1
Deferred income	18.0	15.8
Other postretirement benefits	10.4	10.3
Employee benefits	6.3	7.1
Insurance claims and expenses	9.2	8.1
Deferred payment obligation	9.8	9.6
Accrued development costs	9.2	7.5
Other	6.8	9.9
Total	$ 172.8	$ 104.4