The percentage of aggregate number of common shares reserved for future issuance.

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The anniversary of the share-based compensation arrangement in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Percentage of vesting of share-based compensation awards after the year anniversary of the grant date.

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Percentage of vesting of share-based compensation awards on the one year anniversary of the grant date.

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The number of offering period under the stock based compensation plan.

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The term of offering period under the stock based compensation plan.

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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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Aggregate number of common shares reserved for future issuance.

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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 options awarded to employees as compensation.

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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.

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

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No definition available.

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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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Number of options outstanding, including both vested and non-vested options.

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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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Purchase price of common stock expressed as a percentage of its fair value.

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

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Stock-based Compensation (Details) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Jul. 31, 2019 shares	Sep. 30, 2019 USD ($) $ / shares shares	Sep. 30, 2018 USD ($) $ / shares shares	Sep. 30, 2019 USD ($) $ / shares shares	Sep. 30, 2018 USD ($) $ / shares shares	Dec. 31, 2018 period shares
Stock-based compensation
Common stock available for future grant		8,643,425		8,643,425		6,799,486
Weighted average grant date fair value of options granted \| $ / shares		$ 2.82	$ 8.83	$ 3.70	$ 9.99
Stock based compensation expense \| $		$ 2,572	$ 2,265	$ 7,666	$ 6,417
Inventories \| INVELTYS
Stock-based compensation
Stock based compensation expense \| $		$ 10		$ 400
2017 Equity Incentive Plan
Stock-based compensation
Common stock available for future grant		665,522		665,522
2017 Equity Incentive Plan \| Maximum
Stock-based compensation
Common stock available for future grant		2,538,468		2,538,468
2017 Equity Incentive Plan \| Minimum
Stock-based compensation
Common stock available for future grant						3,573,766
Percentage of aggregate number of common shares reserved for future issuance (as a percent)						4.00%
2009 plan
Stock-based compensation
Common stock available for future grant		2,538,468		2,538,468		2,563,072
Number of shares outstanding		6,995,769		6,995,769		5,111,690
Options granted				2,116,425
Unrecognized compensation expense \| $		$ 20,500		$ 20,500
Weighted average expense recognition period				2 years 5 months 16 days
Employee and Non-Employee Stock Options \| 2009 plan
Stock-based compensation
Options Expiry Term				10 years
Vesting Period				4 years
Performance Stock Options
Stock-based compensation
Number of shares outstanding		0		0
ESPP
Stock-based compensation
Common stock available for future grant		561,971		561,971		223,341
Number of offering period \| period						2
Term of offering period						6 months
Closing price of common stock (as percent)						85.00%
Number of share purchased	123,664
Number of common stock issuable upon exercise of rights under equity compensation plans						223,341
ESPP \| Minimum
Stock-based compensation
Common stock available for future grant						893,441
Percentage of aggregate number of common shares reserved for future issuance (as a percent)						1.00%
Non-statutory Stock Options \| Employee
Stock-based compensation
Options Expiry Term				4 years
Vesting Period				3 years
Percentage of vesting of share-based compensation awards on the one year anniversary of the grant date				25.00%
Anniversary of the share-based compensation arrangement				1 year
Percentage of vesting of share-based compensation awards after the year anniversary of the grant date				75.00%
Options granted		27,000	69,500	175,500	219,500