Employee service share based compensation recognized stock options.

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- Definition

Employee service share based compensation recognized stock options not met.

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Share based compensation arrangement by share based payment award annual increase percentage in number of shares available for grant.

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Share based compensation arrangement by share based payment award offering period discount rate.

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- Definition

Share-based compensation arrangement by share-based payment award payroll deductions offering period.

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- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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- Definition

Aggregate number of common shares reserved for future issuance.

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- Definition

Amount of discretionary contributions made by an employer to a defined contribution plan.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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- Definition

Amount of cost to be recognized for option under share-based payment arrangement.

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- Definition

Amount of cash inflow from exercise of option under share-based payment arrangement.

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- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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- Definition

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 share-based payment arrangement.

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No definition available.

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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

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.

+ References

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- Definition

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

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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.

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- Definition

Number of fully vested and expected to vest options outstanding that can be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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- Definition

Number of shares issued during the period as a result of an employee stock purchase plan.

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

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Stock-Based Compensation - Additional Information (Detail) - USD ($)		1 Months Ended	12 Months Ended
	Jan. 01, 2019	Sep. 30, 2015	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance			16,595,598
Share-based compensation, stock options granted			1,964,025
Share-based compensation, stock options vested			5,655,008
Share-based compensation, stock options cancelled			134,140
Weighted-average grant date fair value of options granted			$ 4.81	$ 6.17	$ 6.68
Stock options exercised, shares			25,857	7,850	46,680
Stock options exercised			$ 178,000	$ 26,000	$ 277,000
Intrinsic value of options exercised			9,000	100,000	200,000
Share based compensation expense, total			6,005,000	6,201,000	5,450,000
Contributions by the company			119,000	126,000	106,000
Performance Based Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to stock option			$ 700,000
Share-based compensation, stock options granted			60,000
Share-based compensation, stock options vested			13,333
Share-based compensation, stock options cancelled			6,667
Stock compensation expense			$ 88,000	142,000	$ 29,000
Service Based Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to stock option			$ 9,400,000
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			4 years
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			3 years
2015 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance			1,750,000
Shares available for issuance			586,554
Common stock outstanding					4.00%
2015 Plan [Member] \| Subsequent Event [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance						1,672,173
2007 and 2015 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to stock option			$ 10,100,000
Weighted average period to recognize compensation expense			2 years 3 months 18 days
2007 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation expense			$ 181,000
Recognized compensation expense related to stock option not met			$ 0
2007 Plan [Member] \| Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option granted to certain employees			583,000
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued under plan			42,818
Periodic payroll deductions offering periods	6 months
Offering period discount rate	15.00%
Share based compensation expense, total			$ 113,000	$ 132,000	$ 42,000
Employee Stock Purchase Plan [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance	1,128,398
Shares authorized for issuance		250,000