Railcar Leasing and Management Services Group (Details 2) - Element Financial Corporation - USD ($) $ in Millions	9 Months Ended		22 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015
Property Subject to or Available for Operating Lease [Line Items]
Proceeds from the sale of leased railcars	$ 616.5	$ 767.9	$ 1,604.2
Rail Group
Property Subject to or Available for Operating Lease [Line Items]
Proceeds from the sale of leased railcars	175.8	153.4
Railcars owned one year or less at the time of sale | Leasing Group
Property Subject to or Available for Operating Lease [Line Items]
Proceeds from the sale of leased railcars	182.7	378.8
Railcars owned more than one year at the time of sale | Leasing Group
Property Subject to or Available for Operating Lease [Line Items]
Proceeds from the sale of leased railcars	$ 258.0	$ 235.7