Unconsolidated Affiliates - Schedule of Equity in Earnings of Unconsolidated Affiliates (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Schedule of Investments [Line Items]
Equity in earnings of unconsolidated affiliates	$ 0.7
International Financial Data Services L.P. [Member]
Schedule of Investments [Line Items]
Equity in earnings of unconsolidated affiliates	0.7	$ 0.7
Pershing Road Development Company, LLC [Member]
Schedule of Investments [Line Items]
Equity in earnings of unconsolidated affiliates	0.7	0.5
Broadway Square Partners, LLP [Member]
Schedule of Investments [Line Items]
Equity in earnings of unconsolidated affiliates	0.3	0.3
Other Unconsolidated Affiliates [Member]
Schedule of Investments [Line Items]
Equity in earnings of unconsolidated affiliates	$ (1.0)	$ (1.5)