Railcar Leasing and Management Services Group (Details 2) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Property Subject to or Available for Operating Lease [Line Items]
Proceeds from sale leased railcars	$ 99.5	$ 171.9
Railcar Leasing and Management Services Group | Railcars owned one year or less at the time of sale
Property Subject to or Available for Operating Lease [Line Items]
Proceeds from sale leased railcars	7.1	126.1
Railcar Leasing and Management Services Group | Railcars owned more than one year at the time of sale
Property Subject to or Available for Operating Lease [Line Items]
Proceeds from sale leased railcars	92.4	37.7
Rail Group
Property Subject to or Available for Operating Lease [Line Items]
Proceeds from sale leased railcars	$ 0.0	$ 8.1