Equity Incentive Plans and Stock-Based Compensation (Details 4)	12 Months Ended
	Dec. 31, 2015 $ / shares shares
Exercise price range 1
Exercise price range
Exercise price range, low end of range (in dollars per share)	$ 4.13
Exercise price range, high end of range (in dollars per share)	$ 5.39
Options Outstanding
Number Outstanding (in shares) | shares	901,728
Weighted Average Remaining Contractual Life (in years)	5 years 11 months 27 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 4.35
Options Exercisable
Number Exercisable (in shares) | shares	125,244
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 4.81
Exercise price range 2
Exercise price range
Exercise price range, low end of range (in dollars per share)	5.46
Exercise price range, high end of range (in dollars per share)	$ 5.46
Options Outstanding
Number Outstanding (in shares) | shares	957,421
Weighted Average Remaining Contractual Life (in years)	6 years 7 months 6 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 5.46
Options Exercisable
Number Exercisable (in shares) | shares	638,284
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 5.46
Exercise price range 3
Exercise price range
Exercise price range, low end of range (in dollars per share)	5.49
Exercise price range, high end of range (in dollars per share)	$ 5.63
Options Outstanding
Number Outstanding (in shares) | shares	885,485
Weighted Average Remaining Contractual Life (in years)	3 years 1 month 17 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 5.63
Options Exercisable
Number Exercisable (in shares) | shares	876,781
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 5.63
Exercise price range 4
Exercise price range
Exercise price range, low end of range (in dollars per share)	5.76
Exercise price range, high end of range (in dollars per share)	$ 5.76
Options Outstanding
Number Outstanding (in shares) | shares	1,210,505
Weighted Average Remaining Contractual Life (in years)	6 years 6 months
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 5.76
Options Exercisable
Number Exercisable (in shares) | shares	522,321
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 5.76
Exercise price range 5
Exercise price range
Exercise price range, low end of range (in dollars per share)	6.39
Exercise price range, high end of range (in dollars per share)	$ 8.55
Options Outstanding
Number Outstanding (in shares) | shares	1,007,877
Weighted Average Remaining Contractual Life (in years)	4 years 9 months 15 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 7.73
Options Exercisable
Number Exercisable (in shares) | shares	940,226
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 7.75
Exercise price range 6
Exercise price range
Exercise price range, low end of range (in dollars per share)	8.73
Exercise price range, high end of range (in dollars per share)	$ 8.73
Options Outstanding
Number Outstanding (in shares) | shares	51,308
Weighted Average Remaining Contractual Life (in years)	7 years 10 months 2 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 8.73
Options Exercisable
Number Exercisable (in shares) | shares	16,781
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 8.73
Exercise price range 7
Exercise price range
Exercise price range, low end of range (in dollars per share)	8.76
Exercise price range, high end of range (in dollars per share)	$ 8.76
Options Outstanding
Number Outstanding (in shares) | shares	1,291,345
Weighted Average Remaining Contractual Life (in years)	7 years 7 months 28 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 8.76
Options Exercisable
Number Exercisable (in shares) | shares	536,793
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 8.76
Exercise price range 8
Exercise price range
Exercise price range, low end of range (in dollars per share)	9.18
Exercise price range, high end of range (in dollars per share)	$ 12.30
Options Outstanding
Number Outstanding (in shares) | shares	941,079
Weighted Average Remaining Contractual Life (in years)	8 years 18 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 11.25
Options Exercisable
Number Exercisable (in shares) | shares	308,564
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 11.15
Exercise price range 9
Exercise price range
Exercise price range, low end of range (in dollars per share)	12.33
Exercise price range, high end of range (in dollars per share)	$ 19.86
Options Outstanding
Number Outstanding (in shares) | shares	981,013
Weighted Average Remaining Contractual Life (in years)	2 years 4 months 6 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 18.01
Options Exercisable
Number Exercisable (in shares) | shares	911,222
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 18.29
Exercise price range 10
Exercise price range
Exercise price range, low end of range (in dollars per share)	20.93
Exercise price range, high end of range (in dollars per share)	$ 40.80
Options Outstanding
Number Outstanding (in shares) | shares	767,256
Weighted Average Remaining Contractual Life (in years)	1 year 8 months 1 day
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 27.55
Options Exercisable
Number Exercisable (in shares) | shares	761,968
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 27.60
Exercise price range 11
Exercise price range
Exercise price range, low end of range (in dollars per share)	4.13
Exercise price range, high end of range (in dollars per share)	$ 40.80
Options Outstanding
Number Outstanding (in shares) | shares	8,995,017
Weighted Average Remaining Contractual Life (in years)	5 years 4 months 28 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 10.01
Options Exercisable
Number Exercisable (in shares) | shares	5,638,184
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 11.58