Long-term Debt (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014
Summary of future contractual minimum rental revenues required under non-cancellable operating leases for railcars
Remaining 6 months of 2014	$ 29,840
2015	59,268
2016	57,550
2017	43,401
2018	31,500
2019 and thereafter	47,724
Total	269,283
Lease Fleet Financing [Member]
Summary of future contractual minimum rental revenues required under non-cancellable operating leases for railcars
Remaining 6 months of 2014	18,115
2015	35,887
2016	35,099
2017	26,458
2018	17,009
2019 and thereafter	31,703
Total	$ 164,271