Railcar Leasing and Management Services Group - Selected consolidating financial information for the Leasing Group (Details) - USD ($) $ in Millions		Sep. 30, 2020		Dec. 31, 2019
Segment Reporting Information [Line Items]
Receivables, net of allowance		$ 219.9		$ 260.1
Property, Plant and Equipment, Net		6,937.9		7,110.6
Restricted cash		101.1		111.4
Other assets		276.6		396.2
Total assets		8,723.2		8,701.4
Total debt		4,935.1		4,881.9
Other liabilities		141.2		96.3
Total liabilities		6,629.6		6,322.5
Noncontrolling interest		276.3		348.8
Total Equity		1,817.3		2,030.1
Operating Segments [Member] | Railcar Leasing and Management Services Group [Member]
Segment Reporting Information [Line Items]
Cash and cash equivalents		2.5		1.8
Receivables, net of allowance		90.5		82.6
Property, Plant and Equipment, Net		7,330.3	[1]	7,605.6
Restricted cash		101.1		111.4
Other assets		39.3		211.2
Total assets		7,563.7		8,012.6
Accounts payable and accrued liabilities		179.0		145.3
Total debt		4,412.0		4,359.1
Deferred income taxes		926.5		862.8
Other liabilities		26.9		32.7
Total liabilities		5,544.4		5,399.9
Noncontrolling interest		276.3		348.8
Total Equity		1,743.0		2,263.9
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Net		(826.8)		(903.8)
Railcar Leasing and Management Services Group [Member]
Segment Reporting Information [Line Items]
Cash and cash equivalents		2.5		1.8
Receivables, net of allowance		90.5		82.6
Property, Plant and Equipment, Net		6,503.5	[1]	6,701.8
Restricted cash		101.1		111.4
Other assets		39.3		211.2
Total assets		6,736.9		7,108.8
Accounts payable and accrued liabilities		179.0		145.3
Total debt		4,412.0		4,359.1
Deferred income taxes		732.7		678.0
Other liabilities		26.9		32.7
Total liabilities		5,350.6		5,215.1
Noncontrolling interest		276.3		348.8
Total Equity		1,110.0		1,544.9
Wholly-owned subsidiaries | Operating Segments [Member] | Railcar Leasing and Management Services Group [Member]
Segment Reporting Information [Line Items]
Cash and cash equivalents		2.5		1.8
Receivables, net of allowance		81.3		73.9
Property, Plant and Equipment, Net		5,692.5	[1]	5,818.9
Restricted cash		73.0		78.4
Other assets		38.1		209.8
Total assets		5,887.4		6,182.8
Accounts payable and accrued liabilities		148.6		100.7
Total debt		3,172.7		3,080.7
Deferred income taxes		925.3		861.7
Other liabilities		26.9		32.7
Total liabilities		4,273.5		4,075.8
Noncontrolling interest		0.0		0.0
Total Equity		1,613.9		2,107.0
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		9.2		8.7
Property, Plant and Equipment, Net		1,637.8	[1]	1,786.7
Restricted cash		28.1		33.0
Other assets		1.2		1.4
Total assets		1,676.3		1,829.8
Accounts payable and accrued liabilities		30.4		44.6
Total debt		1,239.3		1,278.4
Deferred income taxes		1.2		1.1
Other liabilities		0.0		0.0
Total liabilities		1,270.9		1,324.1
Noncontrolling interest		276.3		348.8
Total Equity		129.1		156.9
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	[2]	(826.8)	[1]	(903.8)
Restricted cash		0.0		0.0
Other assets		0.0		0.0
Total assets		(826.8)	[2]	(903.8)
Accounts payable and accrued liabilities		0.0		0.0
Total debt		0.0		0.0
Deferred income taxes	[2]	(193.8)		(184.8)
Other liabilities		0.0		0.0
Total liabilities	[2]	(193.8)		(184.8)
Noncontrolling interest		0.0		0.0
Total Equity	[2]	$ (633.0)		$ (719.0)

[1] See Note 10 for further information regarding impairment of long-lived assets recorded in the nine months ended September 30, 2020.

[2] 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 4 and Note 7 for a further discussion regarding our investment in our partially-owned leasing subsidiaries and the related indebtedness.