Summary of business and significant accounting policies - Research and Software Development Costs (Details) - USD ($) $ in Thousands	12 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Finite-Lived Intangible Assets [Line Items]
Capitalized software development costs	$ 0	$ 0	$ 0
Amortization expense related to capitalized software costs	$ 0	$ 0	$ 0
Minimum
Finite-Lived Intangible Assets [Line Items]
Useful lives/amortization period	3 years
Maximum
Finite-Lived Intangible Assets [Line Items]
Useful lives/amortization period	5 years

Additions made to capitalized computer software costs during the period.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 1
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Amount of expense for amortization of capitalized computer software costs.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 985
-SubTopic 20
-Section 50
-Paragraph 1
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Useful life of finite-lived intangible assets, 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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