Sales (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Sales	$ 92,560	$ 90,501	$ 191,642	$ 179,597
Distillery Products
Disaggregation of Revenue [Line Items]
Sales	75,189	74,023	155,191	148,600
Ingredient Solutions
Disaggregation of Revenue [Line Items]
Sales	17,371	16,478	36,451	30,997
Premium beverage alcohol | Distillery Products
Disaggregation of Revenue [Line Items]
Sales	40,582	42,312	86,554	84,321
Brown goods | Distillery Products
Disaggregation of Revenue [Line Items]
Sales	25,540	27,621	54,610	52,448
White goods | Distillery Products
Disaggregation of Revenue [Line Items]
Sales	15,042	14,691	31,944	31,873
Industrial alcohol | Distillery Products
Disaggregation of Revenue [Line Items]
Sales	22,953	20,636	44,571	41,079
Food grade alcohol | Distillery Products
Disaggregation of Revenue [Line Items]
Sales	63,535	62,948	131,125	125,400
Fuel grade alcohol | Distillery Products
Disaggregation of Revenue [Line Items]
Sales	1,174	1,398	2,696	2,899
Distillers feed and related co-products | Distillery Products
Disaggregation of Revenue [Line Items]
Sales	6,781	6,181	13,770	13,276
Warehouse services | Distillery Products
Disaggregation of Revenue [Line Items]
Sales	3,699	3,496	7,600	7,025
Specialty wheat starches | Ingredient Solutions
Disaggregation of Revenue [Line Items]
Sales	9,122	7,210	19,334	14,090
Specialty wheat proteins | Ingredient Solutions
Disaggregation of Revenue [Line Items]
Sales	6,013	5,276	12,378	9,718
Commodity wheat starches | Ingredient Solutions
Disaggregation of Revenue [Line Items]
Sales	1,774	3,013	3,651	5,275
Commodity wheat proteins | Ingredient Solutions
Disaggregation of Revenue [Line Items]
Sales	$ 462	$ 979	$ 1,088	$ 1,914