Equity Incentive Plans (Details Textual) (USD $)	3 Months Ended	9 Months Ended			0 Months Ended	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2012 2002 Plan [Member]	Feb. 08, 2012 Prior Plans [Member]	Sep. 30, 2012 1997 Plan [Member]	Sep. 30, 2012 2012 Plan [Member]	Sep. 30, 2012 Employee Stock Purchase Plan [Member]	Feb. 08, 2012 Employee Stock Purchase Plan [Member]
Equity Incentive Plans (Textual) [Abstract]
Shares available for issuance under the Plan				52,576			1,577,967
Company's common stock reserved for issuance									300,000
Common stock initially reserved for issuance							3,000,000
Common stock subject to outstanding awards under the Prior Plans						33,461
Common stock maximum under the Plan	200,000,000	200,000,000	68,000,000				1,508,070		3,300,000
Maximum vesting term granted with different vesting terms date of grant							10 years
Shares available for issuance under Plan annual increase shares							2,000,000		300,000
Shares available for issuance under Plan annual increase rate							4.00%		1.00%
Common stock subject to outstanding awards under the Plan	4,385,439	4,385,439	4,385,439				1,485,070
Exercise prices date of grant fair value rate							100.00%
Outstanding options vest							4 years
Total grant vesting							25.00%
Remaining grant vesting		1/36th
Common stock, shares issued	36,204,792	36,204,792	36,204,792					0
Company granted to employees options to purchase		1,508,070			0
Unrecognized compensation expense related to employee stock options	$ 13,700,000							$ 101,000
Equity Incentive Plans (Additional Textual) [Abstract]
Total unrecognized compensation expense related to employee stock options weighted-average period		2 years 10 months 17 days