Railcar Leasing and Management Services Group - Selected consolidating financial information for the Leasing Group (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Consolidating Financial Information
Cash and cash equivalents	$ 102.8	$ 179.2
Property, plant, and equipment, net	6,869.6	6,334.4
Restricted cash	113.7	171.6
Debt:
Long-term Debt, Net of Unamortized Discount, Gross of Unamortized Debt Issuance Costs	399.8	399.7
Less: unamortized debt issuance costs	(2.2)	(2.3)
Debt and Capital Lease Obligations	397.6	397.4
Non-Recourse Debt, Gross of Issuance Cost, Net of Discount	4,252.7	3,664.2
Less: unamortized debt issuance costs	(34.4)	(32.4)
Non-recourse debt, net of unamortized discount and unamortized debt issuance costs	4,218.3	3,631.8
Total debt	4,615.9	4,029.2
Net deferred tax liabilities	754.6	731.6
Railcar Leasing and Management Services Group [Member]
Debt:
Non-recourse debt, net of unamortized discount and unamortized debt issuance costs	4,218.3	3,631.8
Operating Segments
Consolidating Financial Information
Property, plant, and equipment, net	7,731.5	7,162.1
Net deferred profit on railcars sold to the Leasing Group
Consolidating Financial Information
Property, plant, and equipment, net	(861.9)	(827.7)
Wholly-owned subsidiaries
Debt:
Non-recourse debt, net of unamortized discount and unamortized debt issuance costs	2,919.4	2,316.6
Wholly-owned subsidiaries | Railcar Leasing and Management Services Group [Member]
Debt:
Non-Recourse Debt, Gross of Issuance Cost, Net of Discount	2,942.0	2,336.3
Less: unamortized debt issuance costs	(22.6)	(19.7)
Non-recourse debt, net of unamortized discount and unamortized debt issuance costs	2,919.4	2,316.6
Wholly-owned subsidiaries | Operating Segments | Railcar Leasing and Management Services Group [Member]
Consolidating Financial Information
Cash and cash equivalents	2.9	6.0
Property, plant, and equipment, net	5,550.1	4,976.5
Restricted cash	82.8	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 Capital Lease Obligations	0.0	0.0
Non-Recourse Debt, Gross of Issuance Cost, Net of Discount	2,942.0	2,336.3
Less: unamortized debt issuance costs	(22.6)	(19.7)
Non-recourse debt, net of unamortized discount and unamortized debt issuance costs	2,919.4	2,316.6
Total debt	2,919.4	2,316.6
Net deferred tax liabilities	819.3	797.6
Partially-owned subsidiaries
Consolidating Financial Information
Restricted cash	30.8	36.6
Debt:
Non-recourse debt, net of unamortized discount and unamortized debt issuance costs	1,298.9	1,315.2
Partially-owned subsidiaries | Railcar Leasing and Management Services Group [Member]
Debt:
Less: unamortized debt issuance costs	(11.8)	(12.7)
Non-recourse debt, net of unamortized discount and unamortized debt issuance costs	1,298.9	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	1,800.6	1,814.7
Restricted cash	30.8	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 Capital Lease Obligations	0.0	0.0
Non-Recourse Debt, Gross of Issuance Cost, Net of Discount	1,310.7	1,327.9
Less: unamortized debt issuance costs	(11.8)	(12.7)
Non-recourse debt, net of unamortized discount and unamortized debt issuance costs	1,298.9	1,315.2
Total debt	1,298.9	1,315.2
Net deferred tax liabilities	1.0	1.0
Manufacturing/ Corporate
Consolidating Financial Information
Property, plant, and equipment, net	380.8	370.9
Manufacturing/ Corporate | Operating Segments | Manufacturing/ Corporate
Consolidating Financial Information
Cash and cash equivalents	99.9	173.2
Property, plant, and equipment, net	380.8	370.9
Restricted cash	0.1	0.1
Debt:
Long-term Debt, Net of Unamortized Discount, Gross of Unamortized Debt Issuance Costs	399.8	399.7
Less: unamortized debt issuance costs	(2.2)	(2.3)
Debt and Capital Lease Obligations	397.6	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	397.6	397.4
Net deferred tax liabilities	$ (65.7)	$ (67.0)