Sales (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Sales	$ 90,685	$ 95,031	$ 270,282	$ 271,239
Distillery products
Disaggregation of Revenue [Line Items]
Sales	73,295	78,336	221,895	225,365
Ingredient solutions
Disaggregation of Revenue [Line Items]
Sales	17,390	16,695	48,387	45,874
Premium beverage alcohol | Distillery products
Disaggregation of Revenue [Line Items]
Sales	41,965	46,864	126,286	133,135
Brown goods | Distillery products
Disaggregation of Revenue [Line Items]
Sales	26,606	32,137	79,054	88,074
White goods | Distillery products
Disaggregation of Revenue [Line Items]
Sales	15,359	14,727	47,232	45,061
Industrial alcohol | Distillery products
Disaggregation of Revenue [Line Items]
Sales	19,525	20,661	60,604	59,300
Food grade alcohol | Distillery products
Disaggregation of Revenue [Line Items]
Sales	61,490	67,525	186,890	192,435
Fuel grade alcohol | Distillery products
Disaggregation of Revenue [Line Items]
Sales	1,438	1,576	4,337	5,006
Distillers feed and related co-products | Distillery products
Disaggregation of Revenue [Line Items]
Sales	6,630	5,898	19,906	18,785
Warehouse services | Distillery products
Disaggregation of Revenue [Line Items]
Sales	3,737	3,337	10,762	9,139
Specialty wheat starches | Ingredient solutions
Disaggregation of Revenue [Line Items]
Sales	8,432	7,030	22,523	21,170
Specialty wheat proteins | Ingredient solutions
Disaggregation of Revenue [Line Items]
Sales	6,166	5,486	15,884	16,230
Commodity wheat starches | Ingredient solutions
Disaggregation of Revenue [Line Items]
Sales	2,300	2,793	7,575	6,926
Commodity wheat proteins | Ingredient solutions
Disaggregation of Revenue [Line Items]
Sales	$ 492	$ 1,386	$ 2,405	$ 1,548