Accounting policies - Disaggregated revenue (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Total Revenue	$ 19,087,247	$ 18,305,260	$ 39,812,968	$ 35,293,784
Retail revenue [Member]
Total Revenue	5,966,296	6,983,515	13,223,728	13,670,175
Bulk revenue [Member]
Total Revenue	5,866,397	6,941,051	12,306,681	14,052,364
Services revenue [Member]
Total Revenue	3,476,000	90,792	6,590,813	191,369
Manufacturing revenue [Member]
Total Revenue	$ 3,778,554	$ 4,289,902	$ 7,691,746	$ 7,379,876