Leases - Components of lease cost (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Leases
Operating lease costs	$ 191,507	$ 164,040	$ 576,971	$ 404,268
Short-term lease costs		4,119	5,518	12,154
Lease costs - discontinued operations	20,048	54,547	120,753	163,546
Total lease costs	$ 211,555	$ 222,706	$ 703,242	$ 579,968