Equity Incentive Plans and Stock-Based Compensation (Details 3) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Options
Number of Shares
Outstanding, at the beginning of the period (in shares)	11,441,646	11,377,146	13,094,815
Options granted (in shares)	362,335	2,370,313	2,084,276
Options exercised (in shares)	(1,184,141)	(905,464)	(483,923)
Stock options forfeited (in shares)	(1,624,823)	(1,400,349)	(3,318,022)
Outstanding, at the end of the period (in shares)	8,995,017	11,441,646	11,377,146	13,094,815
Vested or expected to vest at the end of the period (in shares)	8,598,752
Options exercisable at the end of the period (in shares)	5,638,184
Weighted Average Exercise Price
Outstanding at the beginning of the year (in dollars per shares)	$ 10.73	$ 11.32	$ 12.79
Options granted (in dollars per share)	11.27	9.63	6.09
Options exercised (in dollars per share)	7.42	6.93	6.72
Options forfeited (in dollars per share)	17.22	16.13	14.51
Outstanding at the end of the period (in dollars per shares)	10.01	$ 10.73	$ 11.32	$ 12.79
Vested or expected to vest at the end of the period (in dollars per share)	10.14
Options exercisable at the end of the period (in dollars per share)	$ 11.58
Weighted Average Remaining Contractual Term (in years)
Outstanding (in years)	5 years 4 months 28 days
Vested or expected to vest (in years)	5 years 3 months 29 days
Options exercisable (in years)	4 years 4 months 28 days
Aggregate Intrinsic Value
Outstanding	$ 32,865
Vested or expected to vest	31,138
Options exercisable	$ 18,386
Closing stock price (in dollars per share)	$ 11.59
Total number of in-the-money outstanding (in shares)	6,981,599
Total number of in-the-money exercisable (in shares)	3,877,529
Stock Options with Market Condition
Number of Shares
Outstanding, at the beginning of the period (in shares)	1,315,000
Options granted (in shares)				1,795,000
Outstanding, at the end of the period (in shares)	1,315,000	1,315,000