Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Balance Sheets [Abstract]
Property and Equipment accumulated depreciation and amortization	$ 15,765	$ 14,963
Patent Costs accumulated amortization	$ 2,199	$ 1,742
Preferred stock, par or stated value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	20,000,000	20,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par or stated value	$ 0.0001	$ 0.0001
Common stock, shares authorized	300,000,000	200,000,000
Common stock, shares, issued	135,743,120	112,352,452
Common stock, shares, outstanding	135,743,120	112,352,452