Condensed Consolidated Balance Sheets (Parenthetical) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Trade accounts receivable less allowances	$ 138,000	$ 171,000
Common stock, par value	$ .01	$ 0.01
Common stock, shares authorized	12,000,000	12,000,000
Common stock, shares issued	9,366,119	9,338,191
Common stock, shares outstanding	9,366,119	9,338,191