Acquisitions - Additional Information (Detail) - USD ($) $ in Millions			12 Months Ended
	Sep. 27, 2024	Oct. 01, 2023	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Business Acquisition [Line Items]
Total revenues			$ 5,882.0	$ 5,502.8	$ 5,283.0
Iress Managed Funds Administration Business [Member]
Business Acquisition [Line Items]
Business acquisition, effective date of acquisition		Oct. 01, 2023
Consideration paid, net of cash plus the costs of transaction		$ 32.5
Total revenues				$ 3.6
Battea Class Action Services [Member]
Business Acquisition [Line Items]
Outstanding stock purchased	$ 671.0
Total revenues			$ 21.1
Battea Class Action Services [Member] | Completed Technology [Member]
Business Acquisition [Line Items]
Amortized period	10 years
Battea Class Action Services [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Amortized period	13 years
Battea Class Action Services [Member] | Trade Names [Member]
Business Acquisition [Line Items]
Amortized period	13 years