Summary of business and significant accounting policies - Leases (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Jul. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets	$ 7,067
Operating lease liabilities	$ 7,978
ASU 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets		$ 11,700
Operating lease liabilities		$ 13,000