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Payments related to stock option.

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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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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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Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

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Unrecognized cost of unvested options awarded to employees as compensation.

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The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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

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

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

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No definition available.

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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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Total number of shares issued during the period, including shares forfeited, as a result of Restricted Stock Awards.

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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 (Details)				1 Months Ended	3 Months Ended		6 Months Ended
	Apr. 17, 2018 Installment shares	Nov. 29, 2017 shares	Oct. 11, 2017 shares	May 31, 2018 $ / shares shares	Jun. 30, 2019 USD ($) shares	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) $ / shares shares	Jun. 30, 2018 USD ($)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Cash proceeds from stock options exercised \| $							$ 9,000
Recognized stock-based compensation expense \| $							$ 1,607,000	$ 1,583,000
Restricted stock award issued					0
Options Issued and Outstanding
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of options exercised							7,029
Cash proceeds from stock options exercised \| $							$ 9,000
Options Issued and Outstanding \| Employees and Directors
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Option granted							1,039,684
Weighted-average grant date fair value of options granted \| $ / shares							$ 6.18
Expense related to options granted \| $					$ 900,000	$ 400,000	$ 1,500,000	700,000
Unrecognized compensation expense \| $					12,000,000		$ 12,000,000
Unrecognized compensation expense, estimated weighted-average period for recognition							3 years 1 month 9 days
Options Issued and Outstanding \| Non-employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Option granted							9,840
Weighted-average grant date fair value of options granted \| $ / shares							$ 5.79
Expense related to options granted \| $					40,000	24,000	$ 48,000	27,000
Unrecognized compensation expense \| $					200,000		$ 200,000
Unrecognized compensation expense, estimated weighted-average period for recognition							2 years 9 months
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares granted	2,000
Number of quarterly installment in which restriction lapse \| Installment	4
Recognized stock-based compensation expense \| $					2,000	10,000	$ 4,000	900,000
Unrecognized stock-based compensation expense \| $					$ 0		$ 0
Unvested Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense, estimated weighted-average period for recognition					2 years 10 months 20 days
Shares granted							0
Recognized stock-based compensation expense \| $					$ 14,000	$ 6,000	$ 28,000	$ 6,000
Unrecognized stock-based compensation expense \| $					$ 200,000		$ 200,000
Unvested Restricted Stock Units \| Non-employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares granted							0
Unvested Restricted Stock Units \| Employees
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares granted				24,960	0
Weighted-average grant date fair value \| $ / shares				$ 9.03
2017 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares reserved for issuance		630,662	537,914		537,914		537,914
Number of additional shares reserved for issuance		1,866,009	630,662
2017 Stock Incentive Plan \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Terms of stock based options granted							10 years
2018 Stock Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of additional shares added on outstanding shares							4.00%
2018 Stock Incentive Plan \| Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares reserved for issuance					2,200,260		2,200,260
2018 Stock Incentive Plan \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares reserved for issuance					3,322,473		3,322,473
2018 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares reserved for issuance					275,030		275,030
Percentage of additional shares added on outstanding shares							1.00%
2018 Employee Stock Purchase Plan \| Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of additional shares reserved for issuance							543,926
2018 Employee Stock Purchase Plan \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of additional shares reserved for issuance							555,583