Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Accounts receivable, allowance for doubtful accounts	$ 1,580	$ 1,635
Property and equipment, accumulated depreciation	$ 4,094	$ 5,451
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	9,000,000	9,000,000
Common stock, shares issued (in shares)	6,472,038	6,472,038
Treasury stock, shares (in shares)	1,314,694	1,314,694