Accounting policies (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Cash and cash equivalents	$ 5,100,000		$ 5,100,000		$ 5,000,000.0
Deposits held in foreign bank	5,100,000		5,100,000
Foreign Currency Transaction Gain (Loss), before Tax [Abstract]
Foreign Currency Transaction Gain (Loss), before Tax	$ 22,077,000	$ (8,068,000)	$ 72,253	$ 20,966
Bahamas [Member]
Deposits held in foreign bank					$ 5,700,000