Railcar Leasing and Management Services Group - Schedule of proceeds from leased railcars (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022		Sep. 30, 2021
Property Subject to or Available for Operating Lease [Line Items]
Lease portfolio sales				$ 514.8		$ 404.5
Operating profit on lease portfolio sales (1)		$ 92.7	$ 78.3	220.5		187.6
Operating Segments [Member]
Property Subject to or Available for Operating Lease [Line Items]
Operating profit on lease portfolio sales (1)		133.9	106.2	333.7		260.0
Operating Segments [Member] | Railcar Leasing and Management Services Group [Member]
Property Subject to or Available for Operating Lease [Line Items]
Operating profit on lease portfolio sales (1)		$ 107.9	$ 109.3	$ 293.2		$ 268.7
Operating Profit Margin		55.40%	58.90%	51.20%		48.50%
Operating Segments [Member] | Sales of Leased Railcars [Domain] | Railcar Leasing and Management Services Group [Member]
Property Subject to or Available for Operating Lease [Line Items]
Lease portfolio sales		$ 299.6	$ 322.1	$ 514.8		$ 410.9
Operating profit on lease portfolio sales (1)		$ 34.3	$ 32.9	$ 73.0	[1]	$ 45.7
Operating Profit Margin		11.40%	10.20%	13.90%		11.10%
Operating Segments [Member] | Sales of Leased Railcars, Excluding Sales-Type Leases | Railcar Leasing and Management Services Group [Member]
Property Subject to or Available for Operating Lease [Line Items]
Operating profit on lease portfolio sales (1)	[2]			$ 71.7

[1] Includes $1.3 million selling profit associated with sales-type leases for the nine months ended September 30, 2022.

[2] Excludes $1.3 million selling profit associated with sales-type leases for the nine months ended September 30, 2022.