Segment information - Property, plant and equipment, net by major geographic region (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Net	$ 57,687,984	$ 61,238,752
Cayman Island [Member]
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Net	28,474,748	29,059,294
Bahamas [Member]
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Net	26,975,427	30,245,741
United States [Member]
Segment Reporting Information [Line Items]
Property, Plant and Equipment, Net	$ 2,237,809	$ 1,933,717