Note 8. Debt Remaining Debt Principal Payments (Details) $ in Millions	Dec. 31, 2019 USD ($)
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	$ 219.3
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Two	237.5
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Three	555.4
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Four	339.1
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Five	758.2
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal after Year Five	2,811.4
Long-term Debt, Gross	4,920.9
Corporate Segment [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	0.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Two	0.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Three	0.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Four	125.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Five	400.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal after Year Five	0.0
Long-term Debt, Gross	525.0
Secured Debt [Member] | 2006 Secured Railcar Equipment Notes [Member] | Railcar Leasing and Management Services Group [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	34.3
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Two	29.1
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Three	29.8
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Four	16.1
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Five	0.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal after Year Five	0.0
Long-term Debt, Gross	109.3
Secured Debt [Member] | 2009 Secured Railcar Equipment Notes [Member] | Railcar Leasing and Management Services Group [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	6.6
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Two	13.4
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Three	14.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Four	11.8
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Five	14.5
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal after Year Five	87.5
Long-term Debt, Gross	147.8
Secured Debt [Member] | 2010 Secured Railcar Equipment Notes [Member] | Railcar Leasing and Management Services Group [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	14.5
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Two	20.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Three	20.9
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Four	22.4
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Five	18.5
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal after Year Five	152.2
Long-term Debt, Gross	248.5
Secured Debt [Member] | 2018 Secured Railcar Equipment Notes [Domain] | Railcar Leasing and Management Services Group [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	20.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Two	20.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Three	20.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Four	20.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Five	20.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal after Year Five	352.3
Long-term Debt, Gross	452.3
Secured Debt [Member] | TRIHC 2018 Secured Railcar Equipment Notes [Member] | Railcar Leasing and Management Services Group [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	10.6
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Two	11.8
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Three	9.3
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Four	11.7
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Five	14.7
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal after Year Five	208.7
Long-term Debt, Gross	266.8
Secured Debt [Member] | 2019 Secured Railcar Equipment Notes [Domain] [Domain] | Railcar Leasing and Management Services Group [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	36.2
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Two	38.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Three	37.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Four	35.1
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Five	36.8
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal after Year Five	718.3
Long-term Debt, Gross	901.4
Secured Debt [Member] | TRL 2012 Secured Railcar Equipment Notes - RIV 2013 [Member] | Railcar Leasing and Management Services Group [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	19.3
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Two	19.9
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Three	19.6
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Four	26.8
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Five	28.9
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal after Year Five	256.9
Long-term Debt, Gross	371.4
Secured Debt [Member] | TRIP Master Funding Secured Railcar Equipment Notes [Member] | Railcar Leasing and Management Services Group [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	32.9
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Two	40.4
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Three	41.8
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Four	37.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Five	191.6
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal after Year Five	574.2
Long-term Debt, Gross	917.9
Promissory Notes [Member] | 2017 Secured Railcar Equipment Notes [Member] [Domain] | Railcar Leasing and Management Services Group [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	33.1
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Two	33.1
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Three	33.2
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Four	33.2
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Five	33.2
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal after Year Five	461.3
Long-term Debt, Gross	627.1
Line of Credit [Member] | TILC Warehouse Facility [Member] | Railcar Leasing and Management Services Group [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	11.8
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Two	11.8
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Three	2.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Four	0.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Five	0.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal after Year Five	0.0
Long-term Debt, Gross	25.6
Line of Credit [Member] | TILC Warehouse Facility Termination Payments [Member] | Railcar Leasing and Management Services Group [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months	0.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Two	0.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Three	327.8
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Four	0.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal in Year Five	0.0
Long-term Debt and Capital Lease Obligations, Maturities, Repayments of Principal after Year Five	0.0
Long-term Debt, Gross	$ 327.8