Stockholders' equity - Narrative - Employee Stock Purchase Plan (Details)	Nov. 20, 2019 period shares	Jun. 30, 2020 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
ESPP shares authorized (in shares)		9,394,000
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
ESPP shares authorized (in shares)	2,500,000
Offering period	12 months
Number of purchase periods \| period	2
Purchase period	6 months
ESPP share purchase price, percent	85.00%

Share-Based Compensation Arrangement By Share-Based Payment Award, Number Of Purchase Periods

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- Definition

Share-Based Compensation Arrangement By Share-Based Payment Award, Offering Period

+ References

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- Definition

Share-Based Compensation Arrangement By Share-Based Payment Award, Purchase Period

+ References

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- Definition

Aggregate number of common shares reserved for future issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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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

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- Definition

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

+ References

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