Leases - Schedule of Maturities of Lease Liabilities (Detail) - USD ($) $ in Millions	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Finance Lease Liabilities, Payments, Due [Abstract]
2020	$ 1.7
2021	1.4
2022	1.0
2023	0.6
2024	0.1
Total lease payments	4.8
Less: imputed interest	(0.6)
Total future lease obligation	4.2		$ 4.9
Operating Lease Liabilities, Payments Due [Abstract]
2020	10.1
2021	8.9
2022	7.0
2023	6.1
2024	3.8
Thereafter	8.8
Total lease payments	44.7
Less: imputed interest	(3.4)
Total future lease obligation	$ 41.3	$ 38.0