CONDENSED BALANCE SHEETS [Parenthetical] - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Allowance for doubtful accounts	$ 58	$ 50
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	$ 9,577	$ 8,900
Preferred stock, par value (in dollars per share)	$ 0.005	$ 0.005
Preferred stock, shares authorized	873	873
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.005	$ 0.005
Common stock, shares authorized	50,000	50,000
Common stock, shares issued	6,128	6,128
Treasury stock, shares	668	668