Note 8. Intangible Assets, Goodwill and Other (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Goodwill [Line Items]
Goodwill	$ 221.5	$ 221.5
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	128.9	126.1
Finite-Lived Intangible Assets, Accumulated Amortization	(41.1)	(30.6)
Finite-Lived Intangible Assets, Net	87.8	95.5
Intangible Assets, Gross (Excluding Goodwill)	140.1	137.3
Intangible Assets, Net (Excluding Goodwill)	99.0	106.7
Amortization of Intangible Assets	10.1	13.0	$ 5.5
Finite-Lived Intangible Asset, Expected Amortization, Year One	9.1
Finite-Lived Intangible Asset, Expected Amortization, Year Two	9.1
Finite-Lived Intangible Asset, Expected Amortization, Year Three	8.7
Finite-Lived Intangible Asset, Expected Amortization, Year Four	6.6
Finite-Lived Intangible Asset, Expected Amortization, Year Five	$ 6.2
Customer-Related Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	14 years 3 months 18 days
Finite-Lived Intangible Assets, Gross	$ 53.6	53.6
Finite-Lived Intangible Assets, Accumulated Amortization	(9.3)	(5.8)
Finite-Lived Intangible Assets, Net	$ 44.3	47.8
Technology-Based Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	9 years 3 months 18 days
Finite-Lived Intangible Assets, Gross	$ 36.8	36.6
Finite-Lived Intangible Assets, Accumulated Amortization	(13.6)	(9.4)
Finite-Lived Intangible Assets, Net	$ 23.2	27.2
Off-Market Favorable Lease
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	12 years 1 month 6 days
Finite-Lived Intangible Assets, Gross	$ 38.5	35.9
Finite-Lived Intangible Assets, Accumulated Amortization	(18.2)	(15.4)
Finite-Lived Intangible Assets, Net	20.3	20.5
Railcar Leasing and Services Group [Member]
Goodwill [Line Items]
Goodwill	50.6	50.6
Rail Products Group [Member]
Goodwill [Line Items]
Goodwill	170.9	170.9
Trade Names
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets (Excluding Goodwill)	11.2	11.2
Impairment of Intangible Assets, Indefinite-Lived (Excluding Goodwill)	$ 0.0	$ 0.0