Leases - Lease assets and liabilities (Details) - USD ($)	Jun. 30, 2022	Dec. 31, 2021
Current
Current assets of discontinued operations		$ 2,654
Noncurrent
Operating lease right-of-use assets	$ 2,298,165	2,681,137
Long-term assets of discontinued operations	12,517	16,898
Total lease right-of-use assets	2,381,032	2,700,689
Current
Current maturities of operating leases	563,643	592,336
Current liabilities of discontinued operations	8,394	11,195
Noncurrent
Noncurrent operating leases	1,850,860	2,137,394
Noncurrent liabilities of discontinued operations	2,921	7,819
Total lease liabilities	$ 2,425,818	$ 2,748,744
Operating leases, weighted average remaining lease term	6 years 9 months 18 days	7 years
Operating leases, weighted average discount rate	5.06%	5.03%
Discontinued Operations.
Noncurrent
Operating leases, weighted average remaining lease term	1 year 4 months 24 days	1 year 7 months 6 days
Operating leases, weighted average discount rate	4.96%	4.77%
Prepaid Expenses and Other Current Assets [Member]
Current
Operating lease assets, current	$ 70,350