Accounting policies - Disaggregated revenue (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Total Revenue	$ 44,237,263	$ 21,067,127	$ 77,106,253	$ 40,625,032
Contracts in progress
Increase in net income	$ 7,323,771	$ 2,289,886	$ 11,137,397	$ 4,006,701
Increase in diluted earnings per share	$ 0.46	$ 0.15	$ 0.70	$ 0.26
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			45 days
Retail revenue [Member]
Total Revenue	$ 7,573,329	$ 6,526,803	$ 15,344,424	$ 12,840,003
Bulk revenue [Member]
Total Revenue	8,482,495	8,423,749	17,486,868	15,774,393
Services revenue [Member]
Total Revenue	24,093,963	5,055,483	36,815,664	9,799,303
Contracts in progress
Increase in net income	$ 1		$ 1
Increase in diluted earnings per share	$ 0.1		$ 0.1
Manufacturing revenue [Member]
Total Revenue	$ 4,087,476	$ 1,061,092	$ 7,459,297	$ 2,211,333