Railcar Leasing and Management Services Group - Selected consolidating financial information for the Leasing Group (Details) - USD ($) $ in Millions		Mar. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Cash and cash equivalents		$ 81.9	$ 79.6
Receivables, net of allowance		333.2	323.5
Property, Plant and Equipment, Net		6,976.5	6,886.8
Restricted cash		181.1	214.7
Other assets		401.4	386.6
Total assets		8,839.2	8,724.3
Debt, Long-Term and Short-Term, Combined Amount		5,707.6	5,607.6
Deferred income taxes		1,133.2	1,134.7
Other liabilities		159.8	163.9
Total liabilities		7,588.8	7,454.7
Noncontrolling interest		256.2	257.2
Total Equity		994.2	1,012.4
Operating Segments [Member] | Railcar Leasing and Management Services Group [Member]
Segment Reporting Information [Line Items]
Cash and cash equivalents		10.5	2.6
Receivables, net of allowance		121.1	100.7
Property, Plant and Equipment, Net		7,398.0	7,309.4
Restricted cash		181.1	214.7
Other assets		206.6	152.5
Total assets		7,917.3	7,779.9
Accounts payable and accrued liabilities		165.1	153.8
Debt, Long-Term and Short-Term, Combined Amount		5,003.3	4,983.5
Deferred income taxes		1,152.4	1,153.4
Other liabilities		37.5	38.8
Total liabilities		6,358.3	6,329.5
Noncontrolling interest		256.2	257.2
Total Equity		1,302.8	1,193.2
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Net		(763.4)	(763.3)
Railcar Leasing and Management Services Group [Member]
Segment Reporting Information [Line Items]
Cash and cash equivalents		10.5	2.6
Receivables, net of allowance		121.1	100.7
Property, Plant and Equipment, Net		6,634.6	6,546.1
Restricted cash		181.1	214.7
Other assets		206.6	152.5
Total assets		7,153.9	7,016.6
Accounts payable and accrued liabilities		165.1	153.8
Debt, Long-Term and Short-Term, Combined Amount		5,003.3	4,983.5
Deferred income taxes		985.2	980.3
Other liabilities		37.5	38.8
Total liabilities		6,191.1	6,156.4
Noncontrolling interest		256.2	257.2
Total Equity		706.6	603.0
Wholly-owned subsidiaries | Operating Segments [Member] | Railcar Leasing and Management Services Group [Member]
Segment Reporting Information [Line Items]
Cash and cash equivalents		10.5	2.6
Receivables, net of allowance		110.7	89.9
Property, Plant and Equipment, Net		5,888.1	5,788.1
Restricted cash		107.0	140.3
Other assets		204.7	150.3
Total assets		6,321.0	6,171.2
Accounts payable and accrued liabilities		125.8	109.7
Debt, Long-Term and Short-Term, Combined Amount		3,826.9	3,800.7
Deferred income taxes		1,151.3	1,152.3
Other liabilities		37.5	38.8
Total liabilities		5,141.5	5,101.5
Noncontrolling interest		0.0	0.0
Total Equity		1,179.5	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		10.4	10.8
Property, Plant and Equipment, Net		1,509.9	1,521.3
Restricted cash		74.1	74.4
Other assets		1.9	2.2
Total assets		1,596.3	1,608.7
Accounts payable and accrued liabilities		39.3	44.1
Debt, Long-Term and Short-Term, Combined Amount		1,176.4	1,182.8
Deferred income taxes		1.1	1.1
Other liabilities		0.0	0.0
Total liabilities		1,216.8	1,228.0
Noncontrolling interest		256.2	257.2
Total Equity		123.3	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]	(763.4)	(763.3)
Restricted cash		0.0	0.0
Other assets		0.0	0.0
Total assets	[1]	(763.4)	(763.3)
Accounts payable and accrued liabilities		0.0	0.0
Debt, Long-Term and Short-Term, Combined Amount		0.0	0.0
Deferred income taxes	[1]	(167.2)	(173.1)
Other liabilities		0.0	0.0
Total liabilities	[1]	(167.2)	(173.1)
Noncontrolling interest		0.0	0.0
Total Equity	[1]	$ (596.2)	$ (590.2)

[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.