Net income (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		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Numerator:
Net income (loss)	$ (17,433)	$ 5,725	$ (28,124)	$ 12,032
Weighted average shares used to compute per share amount:
Basic (in shares)	51,634	49,077	51,178	48,846
Diluted (in shares)	51,634	51,661	51,178	51,124
Basic net income (loss) per share (in dollars per share)	$ (0.34)	$ 0.12	$ (0.55)	$ 0.25
Diluted net income (loss) per share (in dollars per share)	$ (0.34)	$ 0.11	$ (0.55)	$ 0.24