East Dubuque Merger - Summary Pro Forma Financial Information (Details) - East Dubuque Merger - USD ($) $ / shares in Units, $ in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2016 |
Sep. 30, 2015 |
|
| Business Acquisition, Pro Forma Information [Abstract] | ||||
| Net sales | $ 78,473 | $ 96,129 | $ 306,210 | $ 378,806 |
| Net income (loss) | $ (12,257) | $ (10,404) | $ (75) | $ 70,698 |
| Net income (loss) per common unit, basic (in dollars per unit) | $ (0.11) | $ (0.09) | $ 0.00 | $ 0.62 |
| Net income (loss) per common unit, diluted (in dollars per unit) | $ (0.11) | $ (0.09) | $ 0.00 | $ 0.62 |