Notes payable (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Notes payable
October 1, 2020-December 31, 2020	$ 125
January 1, 2021-December 31, 2021	95
Total future minimum payments	220
Less: Imputed interest	(2)
Total current portion of notes payable	$ 218	$ 1,527