Debt and capital lease obligations - Capital lease obligations (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt and capital lease obligations
Current portion of capital lease obligations	$ 277	$ 197
Long-term portion of capital lease obligations	$ 399	$ 277

Present value of lessee's discounted obligation for lease payments from finance lease, classified as noncurrent.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121603541&loc=SL77918627-209977

Name:	us-gaap_FinanceLeaseLiabilityNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant