Railcar Leasing and Management Services Group (Details 2) - Element - USD ($) $ in Millions	6 Months Ended		19 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Proceeds from the sale of leased railcars	$ 349.2	$ 635.7	$ 1,336.9
Rail Group
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Proceeds from the sale of leased railcars	111.7	81.6
Railcars owned one year or less at the time of sale | Leasing Group
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Proceeds from the sale of leased railcars	110.0	331.4
Railcars owned more than one year at the time of sale | Leasing Group
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Proceeds from the sale of leased railcars	$ 127.5	$ 222.7