Commitments and Contingencies - Railcar Operating Leases (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Operating Leased Assets [Line Items] | |||
| Lease revenue | $ 7,710 | $ 13,572 | |
| Railcar | |||
| Operating Leased Assets [Line Items] | |||
| 2016 | 4,630 | ||
| 2017 | 4,698 | ||
| 2018 | 4,054 | ||
| 2019 | 4,054 | ||
| 2020 | 4,054 | ||
| Thereafter | 7,822 | ||
| Total | 29,312 | ||
| Fleet services | |||
| Operating Leased Assets [Line Items] | |||
| Lease revenue | $ 7,710 | $ 8,788 | $ 13,572 |