Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Goodwill [Line Items]
Amortization expense associated with identifiable intangible assets	$ 5.0	$ 4.5	$ 15.0	$ 13.1
Estimated total amortization expense 2024	20.0		20.0
Estimated total amortization expense 2025	17.0		17.0
Estimated total amortization expense 2026	15.3		15.3
Estimated total amortization expense 2027	13.9		13.9
Estimated total amortization expense 2028	12.4		12.4
Indefinite-lived Intangible Assets [Member]
Goodwill [Line Items]
Goodwill and intangible assets with indefinite lives	$ 236.7		$ 236.7		$ 236.7