Slicers (applies to each fact value in each table cell)

Reporting Entity [Axis]

0001406666 (http://www.sec.gov/CIK)

Stockholders' Equity Note [Abstract]	Period [Axis]
	2016-01-01 - 2016-12-31
Stockholders' Equity Note [Abstract]
Schedule of Stock Options Activity	The following table summarizes the activity of stock options under the Company's equity incentive plans (in thousands, except per share data):             Weighted-                 Average             Weighted-   Remaining             Average   Contractual   Aggregate     Number of   Exercise Price   Life   Intrinsic Stock Options   Shares   Per Share   (in years)      Value (1) Outstanding as of December 31, 2015   2,655   $ 11.81         Granted   680   6.96         Exercised   (3 )   5.77         Forfeited   (3 )   7.97         Expired   (120 )   29.31         Outstanding as of December 31, 2016   3,209   $ 10.14   6.3   $ 703 Vested and expected to vest as of December 31, 2016   3,113   $ 10.23   6.1   $ 652 Options exercisable as of December 31, 2016   2,125   $ 11.47   4.9   $ 201                                                                                                    (1) Amounts represent the difference between the exercise price and the fair market value of common stock at December 31, 2016 for all in the money options outstanding.
Schedule of Restricted Stock and Restricted Stock Units Activity	The following table summarizes the activities of the Company's RSUs and PRSUs under the Company's equity incentive plans (in thousands, except per share data):     RSUs   PRSUs         Weighted-       Weighted-         Average       Average         Grant Date       Grant Date     Number of   Fair Value   Number of   Fair Value     Shares   Per Share   Shares   Per Share Outstanding at December 31, 2015   2,469   $ 8.64   184   $ 9.21 Granted   1,287   6.91   550   7.42 Vested   (919 )   8.46   (45 )   11.71 Canceled   (239 )   8.45   (124 )   8.09 Outstanding at December 31, 2016   2,598   $ 7.86   565   $ 7.51
Schedule of Grant Date Fair Values	The following table summarizes the weighted-average grant date fair values of the Company's stock-based awards granted in the periods indicated:     Years Ended December 31,     2016   2015   2014 Stock options   $ 3.58   $ 4.56   $ 4.79 RSUs   $ 6.91   $ 8.59   $ 8.72 PRSUs   $ 7.42   N/A   $ 9.16 ESPP   $ 1.92   $ 2.03   $ 2.46
Valuation Assumptions, Stock Options	The following table summarizes the weighted-average assumptions used in estimating the grant-date fair value of stock options and of each employee's purchase right under the ESPP in the periods indicated:     Years Ended December 31, Stock Options   2016   2015   2014 Expected volatility   53 %   52 %   52 % Expected life (years)   6.25   6.25   6.21 Expected dividend yield   —   —   — Risk-free interest rate   1.60 %   1.56 %   1.87 %
Valuation Assumptions, ESPP	Years Ended December 31, ESPP   2016   2015   2014 Expected volatility   46 %   46 %   45 % Expected life (years)   0.52   0.46   0.50 Expected dividend yield   —   —   — Risk-free interest rate   0.47 %   0.18 %   0.07 %
Schedule of Unrecognized Compensation Cost	As of December 31, 2016, unrecognized stock-based compensation expenses by award type, net of estimated forfeitures, and their expected weighted-average recognition periods are summarized in the following table (in thousands).     As of December 31, 2016     Stock Option   RSU   PRSU   ESPP Unrecognized stock-based compensation expense   $ 3,661   $ 13,380   $ 1,328   $ 721 Weighted-average amortization period (in years)   2.9   2.5   0.9   0.4
Schedule of Warrants	As of December 31, 2016, the following warrants to purchase common stock were outstanding (in thousands, except per share data): Expiration Date    Exercise Price Per Share    Number of Warrants Outstanding September 4, 2017    $ 19.56   15
Shares Reserved For Future Issuance	The Company had common shares reserved for future issuance as follows (in thousands):     As of December 31,     2016   2015   2014 Stock options outstanding   3,209   2,655   3,701 Restricted stock units outstanding   2,598   2,469   1,734 Performance restricted stock units outstanding   565   184   362 Shares available for future grant under 2010 Plan   1,603   2,749   2,283 Shares available for future issuance under ESPP   119   1,129   1,891 Common stock warrants   15   15   15 Total   8,109   9,201   9,986