Property, plant and equipment - Narrative (Details) - USD ($)		12 Months Ended
	Jun. 22, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Depreciation and amortization expense		$ 1,300,000	$ 830,000	$ 171,000
Gross property, plant, and equipment		28,627,477	25,973,037
Payments to acquire property, plant, and equipment		2,316,809	4,009,736	$ 18,893,264
Construction in process
Property, Plant and Equipment [Line Items]
Gross property, plant, and equipment		2,105,873	6,091,265
Building and improvements
Property, Plant and Equipment [Line Items]
Gross property, plant, and equipment		13,297,489	$ 9,244,737
Rollo Bay Farm Site [Member] | Capital Addition Purchase Commitments
Property, Plant and Equipment [Line Items]
Commitments to purchase property, plant, and equipment		257,000
Rollo Bay Farm Site [Member] | Buildings, improvements, and equipment
Property, Plant and Equipment [Line Items]
Gross property, plant, and equipment		5,200,000
Rollo Bay Farm Site [Member] | Construction in process
Property, Plant and Equipment [Line Items]
Gross property, plant, and equipment		1,900,000
Indiana Aquaculture Farm [Member] | Capital Addition Purchase Commitments
Property, Plant and Equipment [Line Items]
Commitments to purchase property, plant, and equipment		216,000
Indiana Aquaculture Farm [Member] | Construction in process
Property, Plant and Equipment [Line Items]
Gross property, plant, and equipment		200,000
Indiana Aquaculture Farm [Member] | Building
Property, Plant and Equipment [Line Items]
Payments to acquire property, plant, and equipment	$ 14,200,000
Indiana Aquaculture Farm [Member] | Building and improvements
Property, Plant and Equipment [Line Items]
Gross property, plant, and equipment		$ 3,200,000