Railcar Leasing and Management Services Group - Selected consolidating financial information for the Leasing Group (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Consolidating Financial Information
Cash and cash equivalents	$ 179.2	$ 1,098.1
Property, plant, and equipment, net	6,334.4	5,557.8
Restricted cash	171.6	195.2
Debt:
Recourse	400.0	877.7
Less: unamortized discount		(8.5)
Less: unamortized debt issuance costs	(2.3)	(2.9)
Recourse, net of unamortized discount and unamortized debt issuance costs	397.4	866.3
Non-recourse	3,666.9	2,401.2
Non-recourse, Unamortized Discount	(2.7)
Less: unamortized debt issuance costs	(32.4)	(25.6)
Non-recourse debt, net of unamortized debt issuance costs	3,631.8	2,375.6
Total debt	4,029.2	3,241.9
Net_deferred_tax_liabilities_(assets)	731.6	709.0
Leasing Group
Debt:
Non-recourse debt, net of unamortized debt issuance costs	3,631.8	2,375.6
Operating Segments
Consolidating Financial Information
Property, plant, and equipment, net	7,162.1	6,358.5
Intersegment
Consolidating Financial Information
Property, plant, and equipment, net	(827.7)	(800.7)
Manufacturing/Corporate
Consolidating Financial Information
Property, plant, and equipment, net	370.9	395.8
Manufacturing/Corporate \| Operating Segments
Consolidating Financial Information
Property, plant, and equipment, net	370.9	395.8
Manufacturing/Corporate \| Operating Segments \| Manufacturing/Corporate
Consolidating Financial Information
Cash and cash equivalents	173.2	1,094.8
Restricted cash	0.1	0.1
Debt:
Recourse	400.0	849.4
Less: unamortized discount		(8.5)
Less: unamortized debt issuance costs	(2.3)	(2.9)
Recourse, net of unamortized discount and unamortized debt issuance costs	397.4	838.0
Non-recourse	0.0	0.0
Non-recourse, Unamortized Discount	0.0
Less: unamortized debt issuance costs	0.0	0.0
Non-recourse debt, net of unamortized debt issuance costs	0.0	0.0
Total debt	397.4	838.0
Net_deferred_tax_liabilities_(assets)	(67.0)	54.5
Partially-owned subsidiaries
Consolidating Financial Information
Restricted cash	36.6	62.9
Debt:
Non-recourse debt, net of unamortized debt issuance costs	1,315.2	1,350.8
Partially-owned subsidiaries \| Leasing Group
Debt:
Non-recourse	1,327.9	1,365.3
Less: unamortized debt issuance costs	(12.7)	(14.5)
Non-recourse debt, net of unamortized debt issuance costs	1,315.2	1,350.8
Partially-owned subsidiaries \| Operating Segments \| Leasing Group
Consolidating Financial Information
Cash and cash equivalents	0.0	0.0
Property, plant, and equipment, net	1,814.7	1,822.7
Restricted cash	36.6	62.9
Debt:
Recourse	0.0	0.0
Less: unamortized discount	0.0	0.0
Less: unamortized debt issuance costs	0.0	0.0
Recourse, net of unamortized discount and unamortized debt issuance costs	0.0	0.0
Non-recourse	1,327.9	1,365.3
Non-recourse, Unamortized Discount	0.0
Less: unamortized debt issuance costs	(12.7)	(14.5)
Non-recourse debt, net of unamortized debt issuance costs	1,315.2	1,350.8
Total debt	1,315.2	1,350.8
Net_deferred_tax_liabilities_(assets)	1.0	0.8
Wholly-owned subsidiaries
Debt:
Non-recourse debt, net of unamortized debt issuance costs	2,316.6	1,024.8
Wholly-owned subsidiaries \| Leasing Group
Debt:
Non-recourse	2,336.3	1,035.9
Less: unamortized debt issuance costs	(19.7)	(11.1)
Non-recourse debt, net of unamortized debt issuance costs	2,316.6	1,024.8
Wholly-owned subsidiaries \| Operating Segments \| Leasing Group
Consolidating Financial Information
Cash and cash equivalents	6.0	3.3
Property, plant, and equipment, net	4,976.5	4,140.0
Restricted cash	134.9	132.2
Debt:
Recourse	0.0	28.3
Less: unamortized discount	0.0	0.0
Less: unamortized debt issuance costs	0.0	0.0
Recourse, net of unamortized discount and unamortized debt issuance costs	0.0	28.3
Non-recourse	2,339.0	1,035.9
Non-recourse, Unamortized Discount	(2.7)
Less: unamortized debt issuance costs	(19.7)	(11.1)
Non-recourse debt, net of unamortized debt issuance costs	2,316.6	1,024.8
Total debt	2,316.6	1,053.1
Net_deferred_tax_liabilities_(assets)	797.6	$ 653.7
Senior notes
Debt:
Less: unamortized discount	(0.3)
Senior notes \| Manufacturing/Corporate \| Operating Segments \| Manufacturing/Corporate
Debt:
Less: unamortized discount	$ (0.3)

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