Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
ASSETS
Other physical property, accumulated depreciation	$ 353	$ 329
CURRENT ASSETS:
Accounts receivables, reserves	$ 305	$ 315
COMMON STOCKHOLDERS' EQUITY:
Common stock, par value (in dollars per share)	$ 0	$ 0
Common stock, authorized (in shares)	46,500,000	46,500,000
Common stock, issued (in shares)	12,852,295	12,812,377
Common stock, outstanding (in shares)	12,852,295	12,812,377
Preferred stock, authorized (in shares)	500,000	500,000
Preferred stock, issued (in shares)	0	0