Equity Incentive Plans (Stock Option Activity) (Details)	9 Months Ended
Sep. 30, 2020 $ / shares shares
Shares Underlying Stock Options
Outstanding beginning balance, Shares underlying stock options and restricted stock awards (in shares) \| shares	5,616,840
Granted, Shares underlying stock options and restricted stock awards (in shares) \| shares	1,802,860
Exercised, Shares underlying stock options and restricted stock awards (in shares) \| shares	(94,219)
Cancelled/Forfeited, Shares underlying stock options and restricted stock awards (in shares) \| shares	(4,000,059)
Outstanding ending balance, Shares underlying stock options and restricted stock awards (in shares) \| shares	3,325,422
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Shares \| shares	1,466,036
Weighted- Average Exercise Price per Share
Outstanding beginning balance, Weighted - average exercise price (usd per share) \| $ / shares	$ 19.50
Granted, Weighted - average exercise price (usd per share) \| $ / shares	4.70
Exercised, Weighted - average exercise price (usd per share) \| $ / shares	6.42
Cancelled/forfeited, Weighted - average exercise price (usd per share) \| $ / shares	18.74
Outstanding ending balance, Weighted - average exercise price (usd per share) \| $ / shares	12.77
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price \| $ / shares	$ 20.53
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	7 years 5 months 4 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term	5 years 6 months 7 days

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Gross number of share options (or share units) granted during the period.

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Number of options outstanding, including both vested and non-vested options.

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-Name Accounting Standards Codification
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Weighted average price at which option holders acquired shares when converting their stock options into shares.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of share options (or share units) exercised during the current period.

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