Railcar Leasing and Management Services Group (Details 3) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property Subject to or Available for Operating Lease [Line Items]
Proceeds from sale leased railcars	$ 171.9	$ 1,180.0	$ 995.3
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	126.1	404.9	486.3
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	37.7	514.6	265.8
Rail Group
Property Subject to or Available for Operating Lease [Line Items]
Proceeds from sale leased railcars	$ 8.1	$ 260.5	$ 243.2