Railcar Leasing and Management Services Group - Selected consolidating financial information for the Leasing Group (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Consolidating Financial Information
Cash and cash equivalents	$ 97.6	$ 179.2
Property, plant, and equipment, net	6,916.7	6,334.4
Restricted cash	117.5	171.6
Debt:
Long-term Debt, Net of Unamortized Discount, Gross of Unamortized Debt Issuance Costs	474.8	399.7
Less: unamortized debt issuance costs	(2.1)	(2.3)
Debt and Lease Obligation	472.7	397.4
Non-Recourse Debt, Gross of Issuance Cost, Net of Discount	4,245.3	3,664.2
Less: unamortized debt issuance costs	(32.8)	(32.4)
Non-recourse debt, net of unamortized discount and unamortized debt issuance costs	4,212.5	3,631.8
Total debt	4,685.2	4,029.2
Deferred Tax Liabilities, Net	769.7	731.6
Railcar Leasing and Management Services Group [Member]
Debt:
Non-recourse debt, net of unamortized discount and unamortized debt issuance costs	4,212.5	3,631.8
Operating Segments
Consolidating Financial Information
Property, plant, and equipment, net	7,787.8	7,162.1
Net deferred profit on railcars sold to the Leasing Group
Consolidating Financial Information
Property, plant, and equipment, net	(871.1)	(827.7)
Wholly-owned subsidiaries
Debt:
Non-recourse debt, net of unamortized discount and unamortized debt issuance costs	2,923.2	2,316.6
Wholly-owned subsidiaries | Railcar Leasing and Management Services Group [Member]
Debt:
Non-Recourse Debt, Gross of Issuance Cost, Net of Discount	2,944.7	2,336.3
Less: unamortized debt issuance costs	(21.5)	(19.7)
Non-recourse debt, net of unamortized discount and unamortized debt issuance costs	2,923.2	2,316.6
Wholly-owned subsidiaries | Operating Segments | Railcar Leasing and Management Services Group [Member]
Consolidating Financial Information
Cash and cash equivalents	4.0	6.0
Property, plant, and equipment, net	5,597.0	4,976.5
Restricted cash	86.5	134.9
Debt:
Long-term Debt, Net of Unamortized Discount, Gross of Unamortized Debt Issuance Costs	0.0	0.0
Less: unamortized debt issuance costs	0.0	0.0
Debt and Lease Obligation	0.0	0.0
Non-Recourse Debt, Gross of Issuance Cost, Net of Discount	2,944.7	2,336.3
Less: unamortized debt issuance costs	(21.5)	(19.7)
Non-recourse debt, net of unamortized discount and unamortized debt issuance costs	2,923.2	2,316.6
Total debt	2,923.2	2,316.6
Deferred Tax Liabilities, Net	833.5	797.6
Partially-owned subsidiaries
Consolidating Financial Information
Restricted cash	30.9	36.6
Debt:
Non-recourse debt, net of unamortized discount and unamortized debt issuance costs	1,289.3	1,315.2
Partially-owned subsidiaries | Railcar Leasing and Management Services Group [Member]
Debt:
Less: unamortized debt issuance costs	(11.3)	(12.7)
Non-recourse debt, net of unamortized discount and unamortized debt issuance costs	1,289.3	1,315.2
Partially-owned subsidiaries | Operating Segments | Railcar Leasing and Management Services Group [Member]
Consolidating Financial Information
Cash and cash equivalents	0.0	0.0
Property, plant, and equipment, net	1,794.5	1,814.7
Restricted cash		36.6
Debt:
Long-term Debt, Net of Unamortized Discount, Gross of Unamortized Debt Issuance Costs	0.0	0.0
Less: unamortized debt issuance costs	0.0	0.0
Debt and Lease Obligation	0.0	0.0
Non-Recourse Debt, Gross of Issuance Cost, Net of Discount	1,300.6	1,327.9
Less: unamortized debt issuance costs	(11.3)	(12.7)
Non-recourse debt, net of unamortized discount and unamortized debt issuance costs	1,289.3	1,315.2
Total debt	1,289.3	1,315.2
Deferred Tax Liabilities, Net	1.0	1.0
Manufacturing/ Corporate
Consolidating Financial Information
Property, plant, and equipment, net	396.3	370.9
Manufacturing/ Corporate | Operating Segments | Manufacturing/ Corporate
Consolidating Financial Information
Cash and cash equivalents	93.6	173.2
Property, plant, and equipment, net	396.3	370.9
Restricted cash	0.1	0.1
Debt:
Long-term Debt, Net of Unamortized Discount, Gross of Unamortized Debt Issuance Costs	474.8	399.7
Less: unamortized debt issuance costs	(2.1)	(2.3)
Debt and Lease Obligation	472.7	397.4
Non-Recourse Debt, Gross of Issuance Cost, Net of Discount	0.0	0.0
Less: unamortized debt issuance costs	0.0	0.0
Non-recourse debt, net of unamortized discount and unamortized debt issuance costs	0.0	0.0
Total debt	472.7	397.4
Deferred Tax Liabilities, Net	$ (64.8)	$ (67.0)