Unconsolidated Affiliates - Schedule of Equity in Earnings of Unconsolidated Affiliates (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Schedule of Investments [Line Items]
Equity in earnings of unconsolidated affiliates	$ (1.0)	$ 2.2	$ (0.3)	$ 2.2
International Financial Data Services L.P. [Member]
Schedule of Investments [Line Items]
Equity in earnings of unconsolidated affiliates	1.0	0.9	1.7	1.6
Pershing Road Development Company, LLC [Member]
Schedule of Investments [Line Items]
Equity in earnings of unconsolidated affiliates	0.4	0.1	1.2	0.6
Broadway Square Partners, LLP [Member]
Schedule of Investments [Line Items]
Equity in earnings of unconsolidated affiliates	0.4	0.3	0.6	0.5
Other Unconsolidated Affiliates [Member]
Schedule of Investments [Line Items]
Equity in earnings of unconsolidated affiliates	$ (2.8)	$ 0.9	$ (3.8)	$ (0.5)