| Schedule of Financial Data for Operating Segments | 
 The following tables set forth certain financial
data for the Company’s operating segments (in thousands): 
  
    |   | 
      | 
    
Three Months Ended  
June 30,
 | 
      | 
      | 
    
Six Months Ended  
June 30,
 | 
      | 
 
    |   | 
      | 
    2017 | 
      | 
      | 
    2016 | 
      | 
      | 
    2017 | 
      | 
      | 
    2016 | 
      | 
 
    |   | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Net Sales | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Ethanol Production: | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Net sales to external customers | 
      | 
    $ | 
    256,125 | 
      | 
      | 
    $ | 
    271,630 | 
      | 
      | 
    $ | 
    499,199 | 
      | 
      | 
    $ | 
    500,871 | 
      | 
 
    | Intersegment net sales | 
      | 
      | 
    188 | 
      | 
      | 
      | 
    260 | 
      | 
      | 
      | 
    499 | 
      | 
      | 
      | 
    523 | 
      | 
 
    | Total ethanol production net sales | 
      | 
      | 
    256,313 | 
      | 
      | 
      | 
    271,890 | 
      | 
      | 
      | 
    499,698 | 
      | 
      | 
      | 
    501,394 | 
      | 
 
    |   | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Marketing and distribution: | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Net sales to external customers | 
      | 
      | 
    149,077 | 
      | 
      | 
      | 
    151,230 | 
      | 
      | 
      | 
    292,343 | 
      | 
      | 
      | 
    264,362 | 
      | 
 
    | Intersegment net sales | 
      | 
      | 
    1,963 | 
      | 
      | 
      | 
    2,091 | 
      | 
      | 
      | 
    3,800 | 
      | 
      | 
      | 
    3,843 | 
      | 
 
    | Total marketing and distribution net sales | 
      | 
      | 
    151,040 | 
      | 
      | 
      | 
    153,321 | 
      | 
      | 
      | 
    296,143 | 
      | 
      | 
      | 
    268,205 | 
      | 
 
    | Intersegment eliminations | 
      | 
      | 
    (2,151 | 
    ) | 
      | 
      | 
    (2,351 | 
    ) | 
      | 
      | 
    (4,299 | 
    ) | 
      | 
      | 
    (4,366 | 
    ) | 
 
    | Net sales as reported | 
      | 
    $ | 
    405,202 | 
      | 
      | 
    $ | 
    422,860 | 
      | 
      | 
    $ | 
    791,542 | 
      | 
      | 
    $ | 
    765,233 | 
      | 
 
    |   | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Cost of goods sold: | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Ethanol production | 
      | 
    $ | 
    253,947 | 
      | 
      | 
    $ | 
    260,237 | 
      | 
      | 
    $ | 
    504,534 | 
      | 
      | 
    $ | 
    496,246 | 
      | 
 
    | Marketing and distribution | 
      | 
      | 
    151,131 | 
      | 
      | 
      | 
    149,521 | 
      | 
      | 
      | 
    294,806 | 
      | 
      | 
      | 
    258,819 | 
      | 
 
    | Intersegment eliminations | 
      | 
      | 
    (1,529 | 
    ) | 
      | 
      | 
    (4,602 | 
    ) | 
      | 
      | 
    (3,678 | 
    ) | 
      | 
      | 
    (8,605 | 
    ) | 
 
    | Cost of goods sold as reported | 
      | 
    $ | 
    403,549 | 
      | 
      | 
    $ | 
    405,156 | 
      | 
      | 
    $ | 
    795,662 | 
      | 
      | 
    $ | 
    746,460 | 
      | 
 
    |   | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Income (loss) before provision for income taxes: | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Ethanol production | 
      | 
    $ | 
    (6,304 | 
    ) | 
      | 
    $ | 
    794 | 
      | 
      | 
    $ | 
    (18,619 | 
    ) | 
      | 
    $ | 
    (16,330 | 
    ) | 
 
    | Marketing and distribution | 
      | 
      | 
    (1,435 | 
    ) | 
      | 
      | 
    2,209 | 
      | 
      | 
      | 
    (1,286 | 
    ) | 
      | 
      | 
    6,178 | 
      | 
 
    | Corporate activities | 
      | 
      | 
    (2,199 | 
    ) | 
      | 
      | 
    1,838 | 
      | 
      | 
      | 
    (3,518 | 
    ) | 
      | 
      | 
    1,767 | 
      | 
 
    |   | 
      | 
    $ | 
    (9,938 | 
    ) | 
      | 
    $ | 
    4,841 | 
      | 
      | 
    $ | 
    (23,423 | 
    ) | 
      | 
    $ | 
    (8,385 | 
    ) | 
 
    | Depreciation and amortization: | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Ethanol production | 
      | 
    $ | 
    9,016 | 
      | 
      | 
    $ | 
    8,793 | 
      | 
      | 
    $ | 
    17,862 | 
      | 
      | 
    $ | 
    17,209 | 
      | 
 
    | Marketing and distribution | 
      | 
      | 
    – | 
      | 
      | 
      | 
    – | 
      | 
      | 
      | 
    – | 
      | 
      | 
      | 
    3 | 
      | 
 
    | Corporate activities | 
      | 
      | 
    283 | 
      | 
      | 
      | 
    225 | 
      | 
      | 
      | 
    546 | 
      | 
      | 
      | 
    458 | 
      | 
 
    |   | 
      | 
    $ | 
    9,299 | 
      | 
      | 
    $ | 
    9,018 | 
      | 
      | 
    $ | 
    18,408 | 
      | 
      | 
    $ | 
    17,670 | 
      | 
 
    | Interest expense: | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
      | 
 
    | Ethanol production | 
      | 
    $ | 
    1,119 | 
      | 
      | 
    $ | 
    6,180 | 
      | 
      | 
    $ | 
    2,211 | 
      | 
      | 
    $ | 
    12,080 | 
      | 
 
    | Marketing and distribution | 
      | 
      | 
    302 | 
      | 
      | 
      | 
    356 | 
      | 
      | 
      | 
    610 | 
      | 
      | 
      | 
    689 | 
      | 
 
    | Corporate activities | 
      | 
      | 
    1,273 | 
      | 
      | 
      | 
    – | 
      | 
      | 
      | 
    2,510 | 
      | 
      | 
      | 
    – | 
      | 
 
    |   | 
      | 
    $ | 
    2,694 | 
      | 
      | 
    $ | 
    6,536 | 
      | 
      | 
    $ | 
    5,331 | 
      | 
      | 
    $ | 
    12,769 | 
      | 
 
 
 |