Investments in Affiliated Companies (Share of Affiliate Earnings) (Details 2) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pre tax share of affiliates earnings by segment
Share of affiliates' earnings (pre-tax)	$ 56.5	$ 95.8	$ 94.5
Provision for Income Taxes, Equity Method Investment	(55.3)	(33.6)	(18.0)
Share of Affiliates' Earnings	1.2	62.2	76.5
Foreign Tax Authority \| United Kingdom tax authority
Pre tax share of affiliates earnings by segment
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount	39.7	12.3
Rail North America [Member]
Pre tax share of affiliates earnings by segment
Share of affiliates' earnings (pre-tax)	0.0	(0.1)	0.0
Rail International [Member]
Pre tax share of affiliates earnings by segment
Share of affiliates' earnings (pre-tax)	0.0	0.0	0.0
Portfolio Management [Member]
Pre tax share of affiliates earnings by segment
Share of affiliates' earnings (pre-tax)	$ 56.5	$ 95.9	$ 94.5

Amount of income (loss) for proportionate share of equity method investee's income (loss).

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