Shareholders' Equity and Share-based Compensation	9 Months Ended
Sep. 30, 2018
Equity [Abstract]
Shareholders' Equity and Share-based Compensation	7. Shareholder’s Equity and Share-based Compensation The Company’s certificate of incorporation as of September 30, 2018 authorized the Company to issue up to 95,000,000 shares of common stock and 5,000,000 shares of preferred stock, each at $0.00001 par value per share. The Company’s certificate of incorporation as of December 31, 2017 authorized the Company to issue up to 400,000,000 shares of common stock and 10,000,000 shares of preferred stock, each at $0.00001 par value per share. As of September 30, 2018, no preferred stock was outstanding. Each share of common stock is entitled to one vote. The holders of common stock are also entitled to receive dividends out of funds legally available. No dividends have been declared to date. 2015 Equity Incentive Plan and 2004 Equity Incentive Plan Under the Company’s 2015 Equity Incentive Plan and 2004 Equity Incentive Plan, shares of common stock were reserved for the issuance of incentive stock options (“ISO”); nonstatutory stock options (“NSO”); or the sales of restricted common stock to employees, officers, directors, and consultants of the Company. The exercise price of an option is determined by the board of directors when the option is granted and may not be less than 85% of the fair market value of the shares on the date of grant, provided that the exercise price of an ISO is not less than 100% of the fair market value of the shares on the date of grant and the exercise price of any option granted to a 10% stockholder is not less than 110% of the fair market value of the shares on the date of grant. ISOs granted under the Plan generally vest 25% after the completion of 12 months of service and the balance in equal monthly installments over the next 36 months of service and expire 10 years from the grant date. NSOs vest as per the specific agreement and expire 10 years from the date of grant. The Plan allows for early exercise of options prior to full vesting as determined by the board of directors and set forth in the stock option agreements governing such options. Exercises of unvested options are subject to repurchase by the Company at not less than the original exercise price upon termination of employment. 2017 Equity Incentive Plan In November 2017, the Company adopted the 2017 Equity Incentive Plan, or 2017 Plan, and all shares reserved for grant under the 2015 Equity Incentive Plan and 2004 Equity Incentive Plan were cancelled. The 2017 Plan had 3,294,919 common shares reserved, plus any shares subject to outstanding stock options or other stock awards that were granted under the 2015 Equity Incentive Plan and 2004 Equity Incentive Plan that were forfeited, terminate, expire or are otherwise not issued. In addition, the shares reserved under the 2017 Plan will automatically increase on the first day of each calendar year, beginning on January 1, 2018 and ending on January 1, 2027, by an amount equal to 5% of the total number of shares of the Company’s capital stock outstanding on the last day of the calendar month before the date of the automatic increase, or a lesser number of shares determined by the board of directors prior to the date of such automatic increase. The 2017 Plan provides for the grant of common stock awards, including incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock and restricted stock units, performance units and performance shares to employees, directors, and consultants of the Company. All granted shares that are canceled, forfeited or expired are returned to the 2017 Plan and are available for grant in conjunction with the issuance of new equity awards. Stock options may be granted at an exercise price per share not less than 100% of the fair market value at the date of grant. If a stock option is granted to a 10% stockholder, then the exercise price per share must not be less than 110% of the fair market value per share of common stock on the grant date. Options granted are exercisable over a maximum term of 10 years from the date of grant and generally vest over a period of four years. As of September 30, 2018, 2,512,698 shares are available for grant.

7. Shareholder’s Equity and Share-based Compensation

The Company’s certificate of incorporation as of September 30, 2018 authorized the Company to issue up to 95,000,000 shares of common stock and 5,000,000 shares of preferred stock, each at $0.00001 par value per share. The Company’s certificate of incorporation as of December 31, 2017 authorized the Company to issue up to 400,000,000 shares of common stock and 10,000,000 shares of preferred stock, each at $0.00001 par value per share.

As of September 30, 2018, no preferred stock was outstanding. Each share of common stock is entitled to one vote. The holders of common stock are also entitled to receive dividends out of funds legally available. No dividends have been declared to date.

2015 Equity Incentive Plan and 2004 Equity Incentive Plan

Under the Company’s 2015 Equity Incentive Plan and 2004 Equity Incentive Plan, shares of common stock were reserved for the issuance of incentive stock options (“ISO”); nonstatutory stock options (“NSO”); or the sales of restricted common stock to employees, officers, directors, and consultants of the Company. The exercise price of an option is determined by the board of directors when the option is granted and may not be less than 85% of the fair market value of the shares on the date of grant, provided that the exercise price of an ISO is not less than 100% of the fair market value of the shares on the date of grant and the exercise price of any option granted to a 10% stockholder is not less than 110% of the fair market value of the shares on the date of grant. ISOs granted under the Plan generally vest 25% after the completion of 12 months of service and the balance in equal monthly installments over the next 36 months of service and expire 10 years from the grant date. NSOs vest as per the specific agreement and expire 10 years from the date of grant. The Plan allows for early exercise of options prior to full vesting as determined by the board of directors and set forth in the stock option agreements governing such options. Exercises of unvested options are subject to repurchase by the Company at not less than the original exercise price upon termination of employment.

2017 Equity Incentive Plan

In November 2017, the Company adopted the 2017 Equity Incentive Plan, or 2017 Plan, and all shares reserved for grant under the 2015 Equity Incentive Plan and 2004 Equity Incentive Plan were cancelled. The 2017 Plan had 3,294,919 common shares reserved, plus any shares subject to outstanding stock options or other stock awards that were granted under the 2015 Equity Incentive Plan and 2004 Equity Incentive Plan that were forfeited, terminate, expire or are otherwise not issued. In addition, the shares reserved under the 2017 Plan will automatically increase on the first day of each calendar year, beginning on January 1, 2018 and ending on January 1, 2027, by an amount equal to 5% of the total number of shares of the Company’s capital stock outstanding on the last day of the calendar month before the date of the automatic increase, or a lesser number of shares determined by the board of directors prior to the date of such automatic increase. The 2017 Plan provides for the grant of common stock awards, including incentive stock options, non-statutory stock options, stock appreciation rights, restricted stock and restricted stock units, performance units and performance shares to employees, directors, and consultants of the Company. All granted shares that are canceled, forfeited or expired are returned to the 2017 Plan and are available for grant in conjunction with the issuance of new equity awards. Stock options may be granted at an exercise price per share not less than 100% of the fair market value at the date of grant. If a stock option is granted to a 10% stockholder, then the exercise price per share must not be less than 110% of the fair market value per share of common stock on the grant date. Options granted are exercisable over a maximum term of 10 years from the date of grant and generally vest over a period of four years. As of September 30, 2018, 2,512,698 shares are available for grant.