Segment information - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Retail [Member]
Segment Reporting Information [Line Items]
Depreciation, Depletion and Amortization	$ 595,247	$ 615,363	$ 1,200,060	$ 1,133,377
Bulk [Member]
Segment Reporting Information [Line Items]
Depreciation, Depletion and Amortization	967,064	976,437	1,934,299	1,924,126
Services [Member]
Segment Reporting Information [Line Items]
Depreciation, Depletion and Amortization	189,723	1,137	373,609	2,273
Manufacturing Units [Member]
Segment Reporting Information [Line Items]
Depreciation, Depletion and Amortization	$ 82,340	$ 215,713	$ 208,474	$ 492,766