Net loss per share - Computation of Basic and Diluted Net Income (Loss) per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Numerator:
Net loss	$ (3,303)	$ (10,692)
Weighted average shares used to compute per share amount:
Weighted average shares used to compute per share amount, basic (in shares)	53,146	50,717
Weighted average shares used to compute per share amount, diluted (in shares)	53,146	50,717
Basic net loss per share (USD per share)	$ (0.06)	$ (0.21)
Diluted net loss per share (USD per share)	$ (0.06)	$ (0.21)