Stock incentive plan (Details)	3 Months Ended
Mar. 31, 2020 shares
2018 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of increase in number of shares outstanding	4.00%
Common stock added to plan	1,349,165
Awards available for future grant	2,758,037
2015 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards available for future grant	505,046

Represents the percentage of increase in number of common shares outstanding on the immediate preceding December 31, or such lesser number of shares determined by the Company’s board of directors or compensation committee of the board of directors.

No definition available.

+ Details

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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.

+ References

No definition available.

+ Details

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- Definition

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

+ References

No definition available.

+ Details

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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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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