Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) shares in Thousands, $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Accounts receivable, reserves	$ 80	$ 210
Common stock, par value (in dollars per share)	$ 1.00	$ 1.00
Common stock, authorized (in shares)	20,000	20,000
Common stock, issued (in shares)	9,082	8,951
Common stock, outstanding (in shares)	9,082	8,951