Note 1. Summary of Significant Accounting Policies Lessee Accounting (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Renewal Term	5 years
Lessee, Operating Lease, Termination Option Term	1 year
Finance Lease, Principal Payments	$ 0.0
Operating Leases, Rent Expense	18.0
Short-term Lease, Cost	4.1
Operating Lease, Right-of-Use Asset	44.2
Operating Lease, Liability, Noncurrent	$ 44.8
Operating Lease, Weighted Average Remaining Lease Term	4 years 9 months 18 days
Operating Lease, Weighted Average Discount Rate, Percent	4.10%
Operating Lease, Payments	$ 18.0
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	10.3
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months	14.0
Lessee, Operating Lease, Liability, Payments, Due Year Two	11.4
Lessee, Operating Lease, Liability, Payments, Due Year Three	10.4
Lessee, Operating Lease, Liability, Payments, Due Year Four	8.1
Lessee, Operating Lease, Liability, Payments, Due Year Five	3.8
Lessee, Operating Lease, Liability, Payments, Due after Year Five	4.4
Lessee, Operating Lease, Liability, Payments, Due	52.1
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	$ (7.3)
Minimum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	1 year
Maximum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	40 years
Railcar Leasing and Management Services Group [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months	$ 10.1
Lessee, Operating Lease, Liability, Payments, Due Year Two	8.6
Lessee, Operating Lease, Liability, Payments, Due Year Three	7.8
Lessee, Operating Lease, Liability, Payments, Due Year Four	5.9
Lessee, Operating Lease, Liability, Payments, Due Year Five	2.7
Lessee, Operating Lease, Liability, Payments, Due after Year Five	1.5
Lessee, Operating Lease, Liability, Payments, Due	36.6
Consolidated Subsidiaries, Excluding Leasing [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months	3.9
Lessee, Operating Lease, Liability, Payments, Due Year Two	2.8
Lessee, Operating Lease, Liability, Payments, Due Year Three	2.6
Lessee, Operating Lease, Liability, Payments, Due Year Four	2.2
Lessee, Operating Lease, Liability, Payments, Due Year Five	1.1
Lessee, Operating Lease, Liability, Payments, Due after Year Five	2.9
Lessee, Operating Lease, Liability, Payments, Due	$ 15.5