Leases - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Lessee Lease Description [Line Items]
Operating lease costs	$ 58.0	$ 66.6	$ 72.3
Cash paid for operating lease liabilities included in operating cashflows	60.7	69.3	74.3
Right-of-use assets obtained in exchange for operating lease liabilities	$ 26.9	$ 22.6
Weighted average remaining lease term	6 years 3 months 18 days	6 years 6 months
Weighted average discount rates	5.30%	5.10%
Real Estate Office Space [Member]
Lessee Lease Description [Line Items]
Total gross sublease and other rental income	$ 7.3	$ 6.3	6.0
Lease Agreements [Member]
Lessee Lease Description [Line Items]
Operating lease expense	$ 1.3	$ 1.3	$ 1.3