Stockholders' Equity (Details Textual 2) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Stockholders Equity (Textual 2) [Abstract]
Minimum voting power percentage for accelerated vesting period	10.00%
RSU awards par value	$ 0.0001	$ 0.0001
Restricted stock units award depletion ratio	1:1.5
Common stock, shares authorized	300,000,000	300,000,000
Maximum 401(k) per employee, percentage of annual salary	60.00%
Matching 401(k) employer contribution, maximum amount	$ 3,000
Compensation expense in connection with 401(k) plan	$ 900,000	$ 1,000,000	$ 800,000
Severance payment period for executives	12 months
Cash severance payment for chief executive officer	24 months base salary plus annual target incentive pay
Severance payment period for employees	6 months
2008 Equity Incentive Plan [Member]
Stockholders Equity (Textual 2) [Abstract]
Number of common stock available for stock options grants	9,000,000
Share-based compensation plan's share limit reduction for every one restricted stock unit granted	1.5
Maximum term of stock options under equity incentive plans	8 years
Minimum voting power percentage for accelerated vesting period	10.00%
Maximum term of incentive stock option for holders of more than ten percent of voting right	5 years
Exercise price of stock options granted	100.00%
Exercise price of stock options granted for holders of more than ten percent of voting right	110.00%
2000 Equity Incentive Plan [Member]
Stockholders Equity (Textual 2) [Abstract]
Maximum term of stock options under equity incentive plans	8 years
Maximum term of incentive stock option for holders of more than ten percent of voting right	5 years
Exercise price of stock options granted	100.00%
Exercise price of stock options granted for holders of more than ten percent of voting right	110.00%
2000 Non-Officer Equity Incentive Plan [Member]
Stockholders Equity (Textual 2) [Abstract]
Maximum term of stock options under equity incentive plans	8 years
Restricted Stock Units [Member]
Stockholders Equity (Textual 2) [Abstract]
RSU awards par value	$ 0.01
Employee Stock Purchase Plan [Member]
Stockholders Equity (Textual 2) [Abstract]
Common stock, shares authorized	1,500,000
Percentage of purchase price of stock	85.00%