Summary of significant accounting policies - Recently issued accounting pronouncements (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Jan. 01, 2022
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease, right-of-use assets	$ 7,189
Operating lease liabilities	8,099
Finance lease, right-of-use assets	341
Finance lease liabilities	$ 357
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease, right-of-use assets		$ 6,000
Operating lease liabilities		7,000
Finance lease, right-of-use assets		400
Finance lease liabilities		$ 400