Note 6. Railcar Leasing and Management Services Group Proceeds from Sale of Railcars (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Property Subject to or Available for Operating Lease [Line Items]
Proceeds From Sale Of Property Subject To Or Available For Operating Lease										$ 750.7	$ 454.3
Total operating profit (loss)		$ 113.5	$ 92.7	$ 73.0	$ 54.8	$ 69.2	$ 78.3	$ 57.8	$ 51.5	334.0	256.8	$ (154.6)
Railcar Leasing and Management Services Group [Member]
Property Subject to or Available for Operating Lease [Line Items]
Total operating profit (loss)										423.3	350.9	353.7
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										$ 750.7	$ 460.7	$ 193.1
Operating Profit Margin										16.80%	11.70%	9.20%
Total operating profit (loss)										$ 127.5	$ 54.1	$ 17.7
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 (loss)										126.2	54.1	17.7
Operating Segments [Member]
Property Subject to or Available for Operating Lease [Line Items]
Total operating profit (loss)										$ 482.4	$ 355.6	$ 390.0
Operating Segments [Member] | Railcar Leasing and Management Services Group [Member]
Property Subject to or Available for Operating Lease [Line Items]
Operating Profit Margin										54.90%	47.70%	44.10%
Total operating profit (loss)	[1]									$ 423.3	$ 350.9	$ 353.7

[1] Operating profit includes: depreciation; fleet operating costs, which include maintenance, compliance, freight, and storage; rent and ad valorem taxes; and selling, engineering, and administrative expenses. Amortization of deferred profit on railcars sold from the Rail Products Group to the Leasing Group is included in the operating profits of the Leasing Group, resulting in the recognition of depreciation expense based on our original manufacturing cost of the railcars. Interest expense is not a component of operating profit and includes the effect of hedges.