Stock Awards (Details Textual) (USD $)	6 Months Ended				3 Months Ended	6 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 29, 2012	Sep. 09, 2011	Jun. 30, 2012 Stock Options [Member]	Jun. 30, 2012 Stock Options [Member]	Jun. 30, 2012 2005 Stock Option Plan [Member]	Jun. 30, 2012 2012 Equity Incentive Plan [Member]	Jun. 30, 2012 2012 Employee Stock Purchase Plan [Member]	Jun. 30, 2012 2005 Stock Plan and 2012 Plan [Member]	Jun. 30, 2012 June 2012 [Member]	Jun. 30, 2012 RSUs [Member]	Jun. 30, 2012 RSUs [Member] 2005 Stock Plan and 2012 Plan [Member]	Jun. 30, 2012 2012 ESPP [Member]
Stock Awards (Textual) [Abstract]
Total shares of common stock reserved for issuance	146,216,915							11,213,927	5,000,000
Number of shares of common stock reserved for issuance, increase, description								January 1 of each year, staring on January 1, 2013 and continuing through January 1, 2022, by up to 5% of the total number of shares of the Company’s common stock outstanding on December 31 of the preceding calendar year as determined by the Company’s board of directors.	January 1 of each calendar year, from January 1, 2013 through January 1, 2022, by up to 1% of the total number of shares of the Company’s common stock outstanding on December 31 of the preceding calendar year.
Total number of shares of common stock outstanding, increase, percentage								5.00%	1.00%
Stock options vesting period	4 years
Stock options granted to new employees vest, percentage per annum										25.00%
Stock options granted from the date the requisite service period begins and continue to vest, continued employment term period (years)										3 years
Options granted, exercisable period (years)	10 years
Stock options subject to performance-based				275,808
Term of certain board-approved financial performance targets	1 year
Target achieved by executive officer	98.00%
Stock options eligible to vest	243,744
Stock-based compensation expense	$ 10,375,000	$ 1,833,000			$ 700,000	$ 800,000
Common Stock Market Price			$ 24.60
Total unrecognized compensation cost, adjusted for estimated forfeitures, related to unvested stock options	74,400,000
Total unrecognized compensation cost, weighted-average remaining vesting period (years)	3 years
Restricted stock, shares issued	263,970	453,243
Unvested shares repurchased	2,084	0
Compensation expense recognized, vesting term	48 months										36 months		3 years 8 months 5 days	6 months
Purchase price of common stock, percent														85.00%
Shares issued under the 2012 ESPP														0
Total unrecognized compensation cost, adjusted for estimated forfeitures, related to unvested RSU's												$ 9,700,000
Weighted-average grant date fair value of the RSUs granted												$ 10.53
Granted RSU												1,032,304