Aggregate number of common shares reserved for future issuance.

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Unrecognized cost of unvested share-based compensation awards.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

General descriptive information regarding an arrangement under which employees and directors receive: (a) awards of equity shares, equity share options, or other equity instruments; or (b) the entity incurs liabilities to them: (1) in amounts based, at least in part, on the price of the entity's shares or other equity instruments; or (2) that require or may require settlement by issuance of the entity's shares. Such an arrangement is usually provided to employees and directors to compensate them, provide performance incentives to them, and to attract or retain their services. May also include pertinent information particular to a plan that is not elsewhere specified in the taxonomy.

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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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- Definition

Number of additional shares authorized for issuance under an established share-based compensation plan.

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No definition available.

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- Definition

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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- Definition

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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- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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- Definition

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

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No definition available.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

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-Publisher FASB
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- Definition

Maximum number of shares that may be issued in accordance with the plan as a proportion of outstanding capital stock.

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- Definition

The number of shares purchased on the open market during the period for issuance to employees under the plan.

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Stock-Based Compensation - Additional Information (Details) - USD ($)			1 Months Ended	12 Months Ended
	Jan. 01, 2019	Oct. 17, 2018	Oct. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2027	Jul. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average fair value of options granted				$ 2.75	$ 1.00
Intrinsic value of share option awards exercised				$ 200,000	$ 686
2018 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock that may be issued		196,000
Plan description		The number of shares of common stock reserved for issuance will automatically increase on January 1 of each calendar year, beginning on January 1, 2019 through January 1, 2028, by the lesser of (1) 1% of the total number of shares of the Company’s common stock outstanding on the last day of the calendar month before the date of the automatic increase, and (2) 490,000 shares; provided that before the date of any such increase, the Company’s board of directors may determine that such increase will be less than the amount set forth in clauses (1) and (2).
Share-based payment award, percentage of outstanding stock Maximum		1.00%
Common stock purchased				0
2018 Employee Stock Purchase Plan \| Scenario, Forecast
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock that may be issued						490,000
Additional shares available for grant to ESPP	244,983
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense				$ 1,600,000
Weighted-average period expected to be recognized				2 years 10 months 24 days
2002 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Additional Common stock reserved for future Issuance							800,000
Number of share grants made under the plan			0
2018 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Additional Common stock reserved for future Issuance				1,670,921
Number of shares of common stock that may be issued		3,231,626
Plan description		The number of shares of common stock reserved for issuance under the 2018 Plan will automatically increase on January 1 of each calendar year, starting on January 1, 2019 through January 1, 2028, in an amount equal to 3% 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 each automatic increase, or a lesser number of shares determined by the Company’s board of directors.
Number of options or stock awards available for grant under the Plan		734,948
Share-based payment award, percentage of outstanding stock Maximum		3.00%
2018 Plan \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock that may be issued		9,694,878