Leases - Lease assets and liabilities (Details) - USD ($)	Sep. 30, 2020	Dec. 31, 2019
Current
Prepaid expenses and other current assets	$ 202,459	$ 33,567
Current assets of discontinued operations		2,530
Noncurrent
Operating lease right-of-use assets	1,414,736	1,811,516
Long-term assets of discontinued operations	41,554	2,627,696
Total lease right-of-use assets	1,658,749	4,475,309
Current
Current maturities of operating leases	545,364	688,540
Current liabilities of discontinued operations	25,918	67,211
Noncurrent
Noncurrent operating leases	1,071,831	1,156,543
Noncurrent liabilities of discontinued operations	8,842	2,679,932
Total lease obligations	$ 1,651,955	$ 4,592,226
Operating leases, weighted average remaining lease term	3 years 6 months	3 years 6 months
Operating leases, weighted average discount rate	4.17%	4.37%
Discontinued Operations
Noncurrent
Operating leases, weighted average remaining lease term	1 year 4 months 24 days	24 years
Operating leases, weighted average discount rate	3.48%	4.68%