Accounting policies - Disaggregated revenue (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Total Revenue	$ 17,103,317	$ 20,725,721
Contracts in progress
Percentage Of Bad Debts	1.00%		1.00%
Minimum [Member]
Contracts in progress
Number of days after consumption billings are collected	30 days
Maximum [Member]
Contracts in progress
Number of days after consumption billings are collected	35 days
Retail revenue [Member]
Total Revenue	$ 5,711,305	7,257,432
Bulk revenue [Member]
Total Revenue	6,245,970	6,440,284
Services revenue [Member]
Total Revenue	3,540,846	3,114,813
Manufacturing revenue [Member]
Total Revenue	$ 1,605,196	$ 3,913,192