Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2013	Dec. 31, 2012
Balance Sheets [Abstract]
Trade accounts receivable, allowance for doubtful accounts	$ 71,000	$ 73,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	12,000,000	12,000,000
Common stock, shares issued	8,749,888	8,749,888
Common stock in treasury, shares	351,503	351,503