Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Sales	$ 92,463	$ 90,685	$ 90,501	$ 89,096	$ 104,850	$ 95,031	$ 88,252	$ 87,956	$ 362,745	$ 376,089	$ 347,448
Distillery Products
Disaggregation of Revenue [Line Items]
Sales									297,233	314,055	291,008
Distillery Products | Brown Goods
Disaggregation of Revenue [Line Items]
Sales									107,190	125,857	113,413
Distillery Products | White Goods
Disaggregation of Revenue [Line Items]
Sales									62,862	62,574	64,585
Distillery Products | Premium beverage alcohol
Disaggregation of Revenue [Line Items]
Sales									170,052	188,431	177,998
Distillery Products | Industrial alcohol
Disaggregation of Revenue [Line Items]
Sales									79,833	80,650	76,636
Distillery Products | Food grade alcohol
Disaggregation of Revenue [Line Items]
Sales									249,885	269,081	254,634
Distillery Products | Fuel grade alcohol
Disaggregation of Revenue [Line Items]
Sales									5,949	6,347	6,368
Distillery Products | Distillers feed and related co-products
Disaggregation of Revenue [Line Items]
Sales									26,743	25,698	19,332
Distillery Products | Warehouse services
Disaggregation of Revenue [Line Items]
Sales									14,656	12,929	10,674
Ingredient Solutions
Disaggregation of Revenue [Line Items]
Sales									65,512	62,034	56,440
Ingredient Solutions | Specialty wheat starches
Disaggregation of Revenue [Line Items]
Sales									30,816	28,594	28,092
Ingredient Solutions | Specialty wheat proteins
Disaggregation of Revenue [Line Items]
Sales									22,359	21,098	19,458
Ingredient Solutions | Commodity wheat starch
Disaggregation of Revenue [Line Items]
Sales									9,628	9,223	8,288
Ingredient Solutions | Commodity wheat protein
Disaggregation of Revenue [Line Items]
Sales									$ 2,709	$ 3,119	$ 602