Condensed Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Allowance for Doubtful Accounts Receivable, Current	$ 154	$ 161
Common stock, par value	$ 0.001	$ 0.001
Common stock, authorized	75,000,000	75,000,000
Common stock, issued	58,722,493	58,577,484
Common stock, outstanding	58,227,793	58,082,784
Treasury Stock, Shares	495,000	495,000
Convertible Preferred Stock [Member]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, authorized	5,000,000	5,000,000
Preferred stock, issued	0	0
Preferred stock, outstanding	0	0