Accounting policies (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Short term deposits	$ 7,738,216	$ 9,275,893
Deposits held in foreign bank	6,400,000
Foreign Currency Transaction Gain (Loss), before Tax [Abstract]
Foreign Currency Transaction Gain (Loss), before Tax	32,594	68,818
Certificate of deposit [Member]
Short term deposits	7,400,000	$ 8,500,000
Deposits held in foreign bank	$ 2,500,000