Equity Incentive Awards - Narrative (Details)	12 Months Ended
Dec. 31, 2018 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Option Exercise Price as Percent of Value of Common Stock	100.00%
Total Shares That May be Issued, Equity Incentive Plan	15,000,000
Options Outstanding, Equity Incentive Plan	5,953,831
Restricted Stock Units Outstanding, Equity Incentive Plan	1,285,752
Stock Options Exercised, Equity Incentive Plan	1,909,515
Shares Issued Pursuant to Restricted Stock Units, Equity Incentive Plan	1,451,648
Shares Issued Pursuant to Stock Bonus Awards, Equity Incentive Plan	113,940
Total value of shares by nonemployee in a year \| $	$ 500,000
Total Shares That May Be Issued, Non-Employee Directors Equity Incentive Plan	600,000
Options Outstanding, Non-Employee Directors Equity Incentive Plan	198,551
Stock Options Exercised, Non-Employee Directors Equity Incentive Plan	0
Shares Issued Pursuant to Restricted Stock Awards, Non-Employee Directors Equity Incentive Plan	103,208
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	7,438,134
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	4,583,555
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Award term	10 years
Restricted Stock \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Restricted Stock \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years

Options to purchase shares outstanding under the Equity Incentive Plan.

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Options to purchase shares outstanding under the Non-Employee Directors Equity Incentive Plan.

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Restricted stock units outstanding under the Equity Incentive Plan.

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Shares issued pursuant to restricted stock awards under the Non-Employee Directors Equity Incentive Plan.

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Shares issued pursuant to restricted stock units under the Equity Incentive Plan.

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Shares issued pursuant to stock bonus awards or restricted stock awards under the Equity Incentive Plan.

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Incentive and nonstatutory stock options have an exercise price of 100% or more of the fair market value of common stock on the date of grant.

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Shares issued upon the exercise of stock options under the Equity Incentive Plan.

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Shares issued upon the exercise of stock options under the Non-Employee Directors Equity Incentive Plan.

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The total number of shares of common stock that may be issued pursuant to stock awards under the Equity Incentive Plan.

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The total number of shares of common stock that may be issued pursuant to stock awards under the Non-Employee Directors Equity Incentive Plan.

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Total value of shares by nonemployee in a year - represents amounts under which non-employee director may be granted awards under the Non-Employee Directors Equity Incentive Plan such that the aggregate grant date fair value may not exceed $500,000 in any calendar year

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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- Definition

Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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