Balance Sheets (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Balance Sheets [Abstract]
Property and Equipment accumulated depreciation and amortization	$ 16,208	$ 15,765
Patent Costs accumulated amortization	$ 2,413	$ 2,199
Preferred stock, par or stated value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	3,333,333	3,333,333
Preferred stock, shares issued
Preferred stock, shares outstanding
Common stock, par or stated value	$ 0.0001	$ 0.0001
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares, issued	22,623,965	22,623,853
Common stock, shares, outstanding	22,623,965	22,623,853