Note receivable (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	6 Months Ended
Mar. 31, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Note receivable [Abstract]
Interest rate			4.50%
Collection of note receivable	$ 1,600		$ 1,598
Interest income		$ 18	$ 17	$ 31

The cash inflow associated with principal collections from a borrowing supported by a written promise to pay an obligation.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3179-108585

Name:	us-gaap_ProceedsFromCollectionOfNotesReceivable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration