Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Trade accounts receivable, less allowance for doubtful accounts	$ 6	$ 6
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	24,088	24,088
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	35,000,000	35,000,000
Common stock, shares issued	28,516,163	28,481,496
Common stock, shares outstanding	28,516,163	28,481,496