Summary of significant accounting policies - Recent accounting pronouncements (Details) $ in Thousands	Jan. 01, 2020 USD ($)
ASU 2016-13 \| Accumulated Deficit
Summary of significant accounting policies
Cumulative-effect adjustment	$ 0

Amount after tax of increase (decrease) to equity or (increase) decrease to net assets, resulting from the cumulative effect adjustment of a new accounting principle applied in the period of adoption.

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant