Railcar Leasing and Management Services Group - Schedule of proceeds from leased railcars (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2022		Mar. 31, 2021
Property Subject to or Available for Operating Lease [Line Items]
Lease portfolio sales		$ 71.1		$ 17.3
Operating profit on lease portfolio sales (1)		54.8		51.5
Railcar Leasing and Management Services Group [Member]
Property Subject to or Available for Operating Lease [Line Items]
Operating profit on lease portfolio sales (1)		79.8		78.3
Operating Segments [Member]
Property Subject to or Available for Operating Lease [Line Items]
Operating profit on lease portfolio sales (1)		80.6		69.5
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)		$ 79.8		$ 78.3
Operating Profit Margin		43.60%		42.70%
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		$ 71.1		$ 17.3
Operating profit on lease portfolio sales (1)		$ 11.8	[1]	$ 1.7
Operating Profit Margin		14.80%		9.80%
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]	$ 10.5

[1] Includes $1.3 million selling profit associated with sales-type leases for the three months ended March 31, 2022.

[2] Excludes $1.3 million selling profit associated with sales-type leases for the three months ended March 31, 2022.