Note 6. Railcar Leasing and Management Services Group Proceeds from Sale of Railcars (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022		Dec. 31, 2021
Property Subject to or Available for Operating Lease [Line Items]
Proceeds From Sale Of Property Subject To Or Available For Operating Lease	$ 381.8	$ 750.7		$ 454.3
Total operating profit	417.0	334.0		256.8
Railcar Leasing and Management Services Group [Member]
Property Subject to or Available for Operating Lease [Line Items]
Total operating profit	428.5	423.3		350.9
Sales of Leased Railcars [Domain] | Railcar Leasing and Management Services Group [Member]
Property Subject to or Available for Operating Lease [Line Items]
Proceeds From Sale Of Property Subject To Or Available For Operating Lease	381.8	750.7		460.7
Total operating profit	$ 82.8	$ 127.5	[1]	$ 54.1
Operating Profit Margin	21.70%	16.80%		11.70%
Sales of Leased Railcars, Excluding Sales Type Lease | Railcar Leasing and Management Services Group [Member]
Property Subject to or Available for Operating Lease [Line Items]
Total operating profit	$ 82.8	$ 126.2	[2]	$ 54.1

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

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