Unconsolidated Affiliates - Schedule of Equity in Earnings of Unconsolidated Affiliates (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Schedule of Investments [Line Items]
Equity in earnings of unconsolidated affiliates, net	$ 2.3	$ 5.7
Orbit Private Investments L.P.
Schedule of Investments [Line Items]
Equity in earnings of unconsolidated affiliates, net	1.2	4.8
International Financial Data Services L.P.
Schedule of Investments [Line Items]
Equity in earnings of unconsolidated affiliates, net	1.5	1.1
Pershing Road Development Company, LLC
Schedule of Investments [Line Items]
Equity in earnings of unconsolidated affiliates, net	(0.1)	(0.2)
Broadway Square Partners, LLP
Schedule of Investments [Line Items]
Equity in earnings of unconsolidated affiliates, net	(0.3)	0.1
Other Unconsolidated Affiliates
Schedule of Investments [Line Items]
Equity in earnings of unconsolidated affiliates, net	$ 0.0	$ (0.1)