Investments in Affiliated Companies (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Alpha Partners Leasing Limited [Domain]
Equity Method Investment, Summarized Financial Information. Revenue.	$ 102.0	$ 95.4	$ 206.0	$ 189.5
Equity Method Investment, Summarized Financial Information, Other Expenses	(88.7)	(81.3)	(175.1)	(152.6)
Equity Method Investment, Summarized Financial Information, Gains (Losses)	15.9	19.6	38.2	26.3
RRPF Joint Ventures [Member]
Equity Method Investment, Summarized Financial Information, Net Income (Loss)	$ 23.6	$ 27.4	$ 55.9	$ 51.2