Condensed Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Accounts receivable, allowance	$ 54	$ 474
Property, plant and equipment, accumulated depreciation	$ 38,845	$ 36,533
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	25,000,000	25,000,000
Common stock, shares issued (in shares)	12,221,484	12,221,484
Common stock, shares outstanding (in shares)	7,353,162	7,224,718
Treasury store shares at cost (in shares)	4,868,322	4,996,766