Leases - Lease assets and liabilities (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Current
Current assets of discontinued operations	$ 7,979	$ 2,654
Noncurrent
Operating lease right-of-use assets	2,058,384	2,681,137
Long-term assets of discontinued operations		16,898
Total lease right-of-use assets	2,101,987	2,700,689
Current
Current maturities of operating leases	546,851	592,336
Current liabilities of discontinued operations	7,361	11,195
Noncurrent
Noncurrent operating leases	1,590,542	2,137,394
Noncurrent liabilities of discontinued operations	0	7,819
Total lease liabilities	$ 2,144,754	$ 2,748,744
Operating leases, weighted average remaining lease term	6 years 7 months 6 days	7 years
Operating leases, weighted average discount rate	5.11%	5.03%
Discontinued Operations.
Noncurrent
Operating leases, weighted average remaining lease term	9 months 18 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	$ 35,624