Leases - Supplemental Balance Sheet Information Related to Leases (Detail) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Operating Leases
Operating lease right-of-use assets	$ 45.1	$ 45.3
Current portion of operating lease liabilities	13.6	13.9
Operating lease liabilities, net of current portion	31.6	31.4
Total operating lease liabilities	$ 45.2	$ 45.3
Weighted average remaining lease term
Operating leases	6 years 2 months 12 days	5 years 6 months
Weighted average discount rate
Operating leases	3.50%	2.60%