Commitments and Contingencies - Components of Lease Cost, Supplemental Cash Flow and Other Information Related to Leases (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Lease, Cost [Abstract]
Operating lease cost	$ 53.5	$ 50.3
Sublease income	(0.3)	(0.9)
Total lease cost	53.2	49.4
Operating cash flows from operating leases	34.3	36.3
Right-of-use assets obtained in exchange for lease obligations	$ 21.5	$ 22.4
Weighted-average remaining lease term of operating leases (years)	5 years 7 months 6 days	6 years
Weighted-average discount rate of operating leases	5.70%	5.60%