Other Assets (Tables)
 12 Months Ended
Dec. 31, 2016
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]  
Summary of prepaid expense and other current assets
Prepaid expenses and other current assets consist of the following at December 31:
 
2016
 
2015
Commodity derivatives and related collateral, net
$
7,127

 
$
10,097

Prepaid expenses
10,665

 
8,504

Deposits
2,897

 
3,824

RIN inventory
9,398

 
5,656

Taxes receivable
4,539

 
1,814

Other
1,646

 
1,987

Total
$
36,272

 
$
31,882
Summary of other noncurrent assets
Other noncurrent assets consist of the following at December 31:
 
2016
 
2015
Spare parts inventory
$
3,532

 
$
2,922

Catalysts
4,479

 
5,742

Deposits
2,392

 
2,370

Other
2,227

 
785

Total
$
12,630

 
$
11,819