Railcar Leasing and Management Services Group - Selected consolidating financial information for the Leasing Group (Details) - USD ($) $ in Millions		Jun. 30, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Cash and cash equivalents		$ 91.7	$ 79.6
Receivables, net of allowance		415.6	323.5
Property, Plant and Equipment, Net		7,029.2	6,886.8
Restricted cash		204.9	214.7
Other assets		421.0	386.6
Total assets		9,022.0	8,724.3
Debt:		5,832.6	5,607.6
Deferred income taxes		1,138.6	1,134.7
Other liabilities		160.4	163.9
Total liabilities		7,773.0	7,454.7
Noncontrolling interest		254.4	257.2
Total Equity		994.6	1,012.4
Operating Segments [Member] | Railcar Leasing and Management Services Group [Member]
Segment Reporting Information [Line Items]
Cash and cash equivalents		6.8	2.6
Receivables, net of allowance		140.2	100.7
Property, Plant and Equipment, Net		7,446.0	7,309.4
Restricted cash		204.9	214.7
Other assets		204.8	152.5
Total assets		8,002.7	7,779.9
Accounts payable and accrued liabilities		175.3	153.8
Debt:		5,038.7	4,983.5
Deferred income taxes		1,152.4	1,153.4
Other liabilities		32.8	38.8
Total liabilities		6,399.2	6,329.5
Noncontrolling interest		254.4	257.2
Total Equity		1,349.1	1,193.2
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Net		(763.8)	(763.3)
Wholly-owned subsidiaries | Operating Segments [Member] | Railcar Leasing and Management Services Group [Member]
Segment Reporting Information [Line Items]
Cash and cash equivalents		6.8	2.6
Receivables, net of allowance		127.5	89.9
Property, Plant and Equipment, Net		5,945.2	5,788.1
Restricted cash		135.8	140.3
Other assets		203.2	150.3
Total assets		6,418.5	6,171.2
Accounts payable and accrued liabilities		134.4	109.7
Debt:		3,870.8	3,800.7
Deferred income taxes		1,151.3	1,152.3
Other liabilities		32.8	38.8
Total liabilities		5,189.3	5,101.5
Noncontrolling interest		0.0	0.0
Total Equity		1,229.2	1,069.7
Partially-owned subsidiaries | Operating Segments [Member] | Railcar Leasing and Management Services Group [Member]
Segment Reporting Information [Line Items]
Cash and cash equivalents		0.0	0.0
Receivables, net of allowance		12.7	10.8
Property, Plant and Equipment, Net		1,500.8	1,521.3
Restricted cash		69.1	74.4
Other assets		1.6	2.2
Total assets		1,584.2	1,608.7
Accounts payable and accrued liabilities		40.9	44.1
Debt:		1,167.9	1,182.8
Deferred income taxes		1.1	1.1
Other liabilities		0.0	0.0
Total liabilities		1,209.9	1,228.0
Noncontrolling interest		254.4	257.2
Total Equity		119.9	123.5
Consolidated Subsidiaries, Leasing [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Cash and cash equivalents		0.0	0.0
Receivables, net of allowance		0.0	0.0
Property, Plant and Equipment, Net	[1]	(763.8)	(763.3)
Restricted cash		0.0	0.0
Other assets		0.0	0.0
Total assets	[1]	(763.8)	(763.3)
Accounts payable and accrued liabilities		0.0	0.0
Debt:		0.0	0.0
Deferred income taxes	[1]	(167.3)	(173.1)
Other liabilities		0.0	0.0
Total liabilities	[1]	(167.3)	(173.1)
Noncontrolling interest		0.0	0.0
Total Equity	[1]	(596.5)	(590.2)
Railcar Leasing and Management Services Group [Member]
Segment Reporting Information [Line Items]
Cash and cash equivalents		6.8	2.6
Receivables, net of allowance		140.2	100.7
Property, Plant and Equipment, Net		6,682.2	6,546.1
Restricted cash		204.9	214.7
Other assets		204.8	152.5
Total assets		7,238.9	7,016.6
Accounts payable and accrued liabilities		175.3	153.8
Debt:		5,038.7	4,983.5
Deferred income taxes		985.1	980.3
Other liabilities		32.8	38.8
Total liabilities		6,231.9	6,156.4
Noncontrolling interest		254.4	257.2
Total Equity		$ 752.6	$ 603.0

[1] Net deferred profit on railcars sold to the Leasing Group consists of intersegment profit that is eliminated in consolidation. Net deferred profit and the related deferred tax impact are included as adjustments to the property, plant, and equipment, net and deferred income taxes line items, respectively, in the Eliminations – Lease Subsidiary column above to reflect the net book value of the railcars purchased by the Leasing Group from the Rail Products Group based on manufacturing cost. See Note 5 and Note 8 for a further discussion regarding our investment in our partially-owned leasing subsidiaries and the related indebtedness.