Investments in Affiliated Companies (Share of Affiliate Earnings) (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pre tax share of affiliates earnings by segment
Share of affiliates' earnings (pre-tax)	$ 45.9	$ 56.5	$ 95.8
Provision for Income Taxes, Equity Method Investment	(12.3)	(55.3)	(33.6)
Share of Affiliates' Earnings	33.6	1.2	62.2
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)	0.5	0.0	(0.1)
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)	$ 45.4	$ 56.5	$ 95.9