Railcar Leasing and Management Services Group - Selected consolidating income statement information for the Leasing Group (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Revenues:
Revenues		$ 641.7	$ 472.7
Operating profit (1):
Total operating profit		69.0	54.8
Select expense information:
Depreciation (3)		74.0	66.9
Selling, engineering, and administrative expenses		49.9	44.7
Profit recognized at sales-type lease commencement (1)	[1]	0.0
Operating Segments [Member]
Revenues:
Revenues		641.7	472.7
Operating profit (1):
Total operating profit		110.8	80.6
Railcar Leasing and Management Services Group [Member] | Operating Segments [Member]
Revenues:
Revenues		203.5	183.1
Operating profit (1):
Total operating profit	[2]	$ 85.5	$ 79.8
Operating Income (Loss), Percent Change		7.10%
Operating Profit Margin		42.00%	43.60%
Select expense information:
Depreciation (3)	[2],[3]	$ 62.4	$ 57.2
Depreciation, Depletion, and Amortization, Percent Change	[2],[3]	9.10%
Maintenance and compliance	[2]	$ 35.8	29.2
Maintenance Costs, Percent Change	[2]	22.60%
Operating lease expense	[2]	$ 4.3	5.0
Operating Leases, Rent Expense, Percent Change	[2]	(14.00%)
Selling, engineering, and administrative expenses	[2]	$ 15.7	12.8
Selling, Engineering, and Administrative Expense, Percent Change	[2]	22.70%
Interest		$ 54.8	38.7
Interest Expense, Percent Change		41.60%
Railcar Leasing and Management Services Group [Member] | Operating Segments [Member] | Sustainable Railcar Conversions
Select expense information:
Depreciation (3)		$ 4.7	2.2
Railcar Leasing and Management Services Group [Member] | Operating Segments [Member] | Leasing and Management [Member]
Revenues:
Revenues		$ 203.5	183.1
Revenues, Percent Change		11.10%
Operating profit (1):
Total operating profit	[2]	$ 72.0	$ 68.0
Operating Income (Loss), Percent Change		5.90%
Operating Profit Margin		35.40%	37.10%
Railcar Leasing and Management Services Group [Member] | Operating Segments [Member] | Sales of Leased Railcars [Domain]
Operating profit (1):
Total operating profit	[2]	$ 13.5	$ 11.8	[4]
Operating Profit Margin		23.80%	14.80%
Select expense information:
Profit recognized at sales-type lease commencement (1)	[1]		$ 1.3

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

[2] 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.

[3] Depreciation expense includes $4.7 million and $2.2 million for the three months ended March 31, 2023 and 2022, respectively, related to the disposal of certain railcar components associated with our sustainable railcar conversion program.

[4] Includes $1.3 million selling profit associated with sales-type leases for the three months ended March 31, 2022.