CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Accounts receivable, allowance	$ 0	$ 5
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000	5,000
Preferred stock, shares issued	0	3
Preferred stock, shares outstanding	0	3
Preferred stock, liquidation preference	$ 0	$ 9,496
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	112,500	112,500
Common stock, shares issued	56,252	51,211
Common stock, shares outstanding	56,252	51,211