Railcar Leasing and Management Services Group - Selected consolidating income statement information for the Leasing Group (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022		Sep. 30, 2021
Revenues:
Revenues		$ 496.6	$ 419.8	$ 1,386.1		$ 1,043.8
Operating profit (1):
Total operating profit		92.7	78.3	220.5		187.6
Select expense information:
Depreciation (3)				206.0		200.4
Selling, engineering, and administrative expenses		48.0	45.8	137.7		136.7
Profit recognized at sales-type lease commencement (1)		0.0	0.0	1.3	[1]	0.0
Loss on extinguishment of debt		0.0	0.0	1.5		11.7
Sustainable Railcar Conversions
Select expense information:
Depreciation (3)		2.4	4.7	8.5		7.3
Operating Segments [Member]
Revenues:
Revenues		496.6	419.8	1,386.1		1,043.8
Operating profit (1):
Total operating profit		133.9	106.2	333.7		260.0
Railcar Leasing and Management Services Group [Member] | Operating Segments [Member]
Revenues:
Revenues		194.8	185.5	573.2		554.1
Operating profit (1):
Total operating profit		$ 107.9	$ 109.3	$ 293.2		$ 268.7
Operating Income (Loss), Percent Change		(1.30%)		9.10%
Operating Profit Margin		55.40%	58.90%	51.20%		48.50%
Select expense information:
Depreciation (3)	[2],[3]	$ 59.1	$ 58.7	$ 175.7		$ 170.5
Depreciation, Depletion, and Amortization, Percent Change	[2],[3]	0.70%		3.00%
Maintenance and compliance	[3]	$ 28.2	22.8	$ 84.7		73.7
Maintenance Costs, Percent Change	[3]	23.70%		14.90%
Operating Leases, Rent Expense, Percent Change	[3]	4.00%		8.40%
Operating lease expense	[3]	$ 5.2	5.0	$ 15.5		14.3
Selling, engineering, and administrative expenses	[3]	$ 14.2	11.6	$ 39.6		36.1
Selling, Engineering, and Administrative Expense, Percent Change	[3]	22.40%		9.70%
Interest (4)		$ 49.2	39.9	$ 133.9	[4]	142.6	[4]
Interest Expense, Percent Change		23.30%		(6.10%)	[4]
Railcar Leasing and Management Services Group [Member] | Operating Segments [Member] | Leasing and Management [Member]
Revenues:
Revenues		$ 194.8	185.5	$ 573.2		554.1
Revenues, Percent Change		5.00%		3.40%
Operating profit (1):
Total operating profit		$ 73.6	$ 76.4	$ 220.2		$ 223.0
Operating Income (Loss), Percent Change		(3.70%)		(1.30%)
Operating Profit Margin		37.80%	41.20%	38.40%		40.20%
Railcar Leasing and Management Services Group [Member] | Operating Segments [Member] | Sales of Leased Railcars [Domain]
Operating profit (1):
Total operating profit		$ 34.3	$ 32.9	$ 73.0	[5]	$ 45.7
Operating Profit Margin		11.40%	10.20%	13.90%		11.10%

[1] Included in gains on dispositions of property – lease portfolio sales on our Consolidated Statements of Operations.

[2] Depreciation expense includes $2.4 million and $8.5 million for the three and nine months ended September 30, 2022, respectively, related to the disposal of certain railcar components associated with our sustainable railcar conversion program. For the three and nine months ended September 30, 2021, depreciation expense includes $4.7 million and $7.3 million, respectively, related to our sustainable railcar conversion program.

[3] 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 profit 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.

[4] Interest expense for the nine months ended September 30, 2022 includes $1.5 million of loss on extinguishment of debt associated with the repayment of TRIP Railcar Co.'s outstanding term loan agreement. Interest expense for the nine months ended September 30, 2021 includes $11.7 million of loss on extinguishment of debt associated with the refinancing of our partially-owned subsidiaries' debt.

[5] Includes $1.3 million selling profit associated with sales-type leases for the nine months ended September 30, 2022.