Note 6. Railcar Leasing and Management Services Group Other Operating Lease Obligations and Revenues (Details) $ in Millions	Dec. 31, 2020 USD ($)
Sale Leaseback Transaction [Line Items]
Lessee, Operating Lease, Liability, to be Paid	$ 120.2
Railcar Leasing and Management Services Group [Member]
Sale Leaseback Transaction [Line Items]
Minimum Lease Payments, Sale Leaseback Transactions, Next Twelve Months	8.2
Minimum Lease Payments, Sale Leaseback Transactions, within Two Years	7.5
Minimum Lease Payments, Sale Leaseback Transactions, within Three Years	5.7
Minimum Lease Payments, Sale Leaseback Transactions, within Four Years	2.5
Minimum Lease Payments, Sale Leaseback Transactions, within Five Years	0.6
Minimum Lease Payments, Sale Leaseback Transactions, Thereafter	0.3
Minimum Lease Payments, Sale Leaseback Transactions	24.8
Lessee, Operating Lease, Liability, to be Paid	26.8
Railcar Leasing and Management Services Group [Member] | Property Lease Guarantee [Member]
Sale Leaseback Transaction [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	2.0
Other Third Parties [Member] | Railcar Leasing and Management Services Group [Member]
Sale Leaseback Transaction [Line Items]
Future Minimum Sublease Rentals, Sale Leaseback Transactions, Next Twelve Months	5.0
Future Minimum Sublease Rentals, Sale Leaseback Transactions, within Two Years	3.4
Future Minimum Sublease Rentals, Sale Leaseback Transactions, within Three Years	1.6
Future Minimum Sublease Rentals, Sale Leaseback Transactions, within Four Years	0.7
Future Minimum Sublease Rentals, Sale Leaseback Transactions, within Five Years	0.2
Future Minimum Sublease Rentals, Sale Leaseback Transactions, Thereafter	0.0
Future Minimum Sublease Rentals, Sale Leaseback Transactions	10.9
Building [Member] | Railcar Leasing and Management Services Group [Member]
Sale Leaseback Transaction [Line Items]
Lessee, Operating Lease, Liability, to be Paid	$ 2.0