Condensed Consolidated Balance Sheets (Unaudited) (Parentheticals) - USD ($)	Mar. 31, 2022	Dec. 31, 2021	[1]
Allowance for doubtful accounts	$ 71,000	$ 64,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	50,000,000	50,000,000
Common stock, shares outstanding (in shares)	12,945,341	13,115,341

[1] The condensed consolidated balance sheet as of December 31, 2021 has been prepared using information from the audited consolidated balance sheet as of that date.