Number of vesting installments.

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- Definition

Share-based compensation arrangement by share-based payment award, number of additional shares authorized annual increase percentage.

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- Definition

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

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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 nonvested award under share-based payment arrangement. Excludes share and unit options.

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- Definition

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

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Description of service or performance condition required to be met for earning right to award under share-based payment arrangement. Includes, but is not limited to, combination of market, performance or service condition.

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- Definition

Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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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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No definition available.

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Number of shares authorized for issuance under share-based payment arrangement.

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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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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 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

Percentage of vesting of award under share-based payment arrangement.

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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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Share-Based Compensation - Additional Information (Details) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($) shares	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) Installment $ / shares shares	Jun. 30, 2019 USD ($)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expenses	$ 646	$ 1,022	$ 1,842	$ 1,523
Weighted-average grant-date fair value of stock options granted \| $ / shares			$ 1.52
Intrinsic value of stock options exercised			$ 200
Stock Options Outstanding
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expenses	300	700	800	1,000
Unrecognized compensation cost related to non-vested stock options	2,800		$ 2,800
Non-vested awards not yet recognized weighted-average period for recognition			2 years 7 months 6 days
Restricted Stock Awards and Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expenses	400	$ 300	$ 1,000	$ 500
Non-vested awards not yet recognized weighted-average period for recognition			2 years 3 months 18 days
Unrecognized compensation cost related to non-vested restricted stock	$ 4,800		$ 4,800
Fair value of restricted stock vested			$ 200
2018 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Annual percentage increase in number of shares authorized for issuance			4.00%
Vesting terms of stock options			stock options vest 25% upon the first anniversary of the date of grant and the remainder ratably monthly thereafter for 36 months. Restricted stock awards and restricted stock units vest ratably in three equal installments on the first, second and third anniversaries of the grant date.
Number of vesting installments \| Installment			3
Shares available for future issuance \| shares	1,300,000		1,300,000
2018 Equity Incentive Plan \| First Anniversary of Date of Grant
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting percentage of stock options			25.00%
2018 Equity Incentive Plan \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized for issuance \| shares	1,400,000		1,400,000
Maximum contractual term of stock options			10 years