Railcar Leasing and Management Services Group - Selected consolidating financial information for the Leasing Group (Details) - USD ($) $ in Millions	Sep. 30, 2017		Dec. 31, 2016
Consolidating Financial Information
Cash, cash equivalents, and short-term marketable securities	$ 1,024.7		$ 798.1
Property, plant, and equipment, net	6,070.1	[1]	5,966.8
Restricted cash	176.3	[1]	178.2
Debt:
Recourse	879.3		881.5
Less: unamortized discount	(13.2)	[1]	(27.1)
Less: unamortized debt issuance costs	(3.2)		(3.8)
Recourse, net of unamortized discount and unamortized debt issuance costs	862.9	[1]	850.6
Non-recourse	2,440.5		2,232.4
Less: unamortized debt issuance costs	(27.0)		(26.4)
Non-recourse debt, net of unamortized debt issuance costs	2,413.5		2,206.0
Total debt	3,276.4	[1]	3,056.6
Net deferred tax liabilities	1,230.5		1,057.0
Leasing Group
Debt:
Non-recourse debt, net of unamortized debt issuance costs	2,413.5		2,206.0
Operating Segments
Consolidating Financial Information
Property, plant, and equipment, net	6,865.7		6,764.9
Net deferred profit on railcars sold to the Leasing Group
Consolidating Financial Information
Property, plant, and equipment, net	(795.6)		(798.1)
Wholly-owned subsidiaries
Debt:
Non-recourse debt, net of unamortized debt issuance costs	1,054.1	[1]	840.0
Wholly-owned subsidiaries | Leasing Group
Debt:
Non-recourse	1,066.1		851.4
Less: unamortized debt issuance costs	(12.0)		(11.4)
Non-recourse debt, net of unamortized debt issuance costs	1,054.1		840.0
Wholly-owned subsidiaries | Operating Segments | Leasing Group
Consolidating Financial Information
Cash, cash equivalents, and short-term marketable securities	7.8		7.2
Property, plant, and equipment, net	4,073.5		3,923.6
Restricted cash	109.6		99.7
Debt:
Recourse	29.4		32.1
Less: unamortized discount	0.0		0.0
Less: unamortized debt issuance costs	(0.1)		(0.1)
Recourse, net of unamortized discount and unamortized debt issuance costs	29.3		32.0
Non-recourse	1,066.1		851.4
Less: unamortized debt issuance costs	(12.0)		(11.4)
Non-recourse debt, net of unamortized debt issuance costs	1,054.1		840.0
Total debt	1,083.4		872.0
Net deferred tax liabilities	1,047.8		956.6
Partially-owned subsidiaries
Consolidating Financial Information
Restricted cash	66.6	[1]	78.4
Debt:
Non-recourse debt, net of unamortized debt issuance costs	1,359.4	[1]	1,366.0
Partially-owned subsidiaries | Leasing Group
Debt:
Non-recourse	1,374.4		1,381.0
Less: unamortized debt issuance costs	(15.0)		(15.0)
Non-recourse debt, net of unamortized debt issuance costs	1,359.4		1,366.0
Partially-owned subsidiaries | Operating Segments | Leasing Group
Consolidating Financial Information
Cash, cash equivalents, and short-term marketable securities	0.1		0.0
Property, plant, and equipment, net	1,836.5		1,879.6
Restricted cash	66.6		78.4
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	1,374.4		1,381.0
Less: unamortized debt issuance costs	(15.0)		(15.0)
Non-recourse debt, net of unamortized debt issuance costs	1,359.4		1,366.0
Total debt	1,359.4		1,366.0
Net deferred tax liabilities	2.0		2.0
Manufacturing/ Corporate
Consolidating Financial Information
Property, plant, and equipment, net	955.7		961.7
Manufacturing/ Corporate | Operating Segments
Consolidating Financial Information
Property, plant, and equipment, net	955.7		961.7
Manufacturing/ Corporate | Operating Segments | Manufacturing/ Corporate
Consolidating Financial Information
Cash, cash equivalents, and short-term marketable securities	1,016.8		790.9
Restricted cash	0.1		0.1
Debt:
Recourse	849.9		849.4
Less: unamortized discount	(13.2)		(27.1)
Less: unamortized debt issuance costs	(3.1)		(3.7)
Recourse, net of unamortized discount and unamortized debt issuance costs	833.6		818.6
Non-recourse	0.0		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	833.6		818.6
Net deferred tax liabilities	$ 180.7		$ 98.4

[1] (unaudited)