Commitments and Contingencies (Tables)
12 Months Ended
Dec. 31, 2015
Commitments and Contingencies Disclosure [Abstract]  
Schedule of contractual obligations, fiscal year maturities
The approximate amount of our future minimum lease payments under non-cancellable operating leases are as follows (in thousands):
 
Year ending December 31,
2016
$
4,734

2017
4,805

2018
4,071

2019
4,071

2020
4,072

Thereafter
7,880

Total
$
29,633

The future minimum payments for these rail services agreements are as follows (in thousands):
 
Year ending December 31,
2016
$
6,974

2017
5,971

2018
6,096

2019
3,719

Total
$
22,760

The following table presents future minimum lease rentals due to us under non-cancellable railcar operating leases (in thousands):
 
Year ending December 31,
2016
$
4,630

2017
4,698

2018
4,054

2019
4,054

2020
4,054

Thereafter
7,822

Total
$
29,312