Fair value measurements - Summary of Changes in Fair Value for Fair Value was Determined by Level 3 Inputs (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)
Schedule Of Changes In Fair Value [Line Items]
Change in fair value	$ 757
Level 3 [Member] | Warrants [Member]
Schedule Of Changes In Fair Value [Line Items]
Beginning balance-Derivative Liabilities	461
Exercise of warrants	(137)
Change in fair value	296
Retirement of liability	(620)
Ending balance-Derivative Liabilities	0
Level 3 [Member] | Mandatorily Redeemable Preferred Stock [Member]
Schedule Of Changes In Fair Value [Line Items]
Beginning balance- Redeemable Convertible Preferred Stock Liability	3,174
Exercise of warrants	0
Change in fair value	11,386
Retirement of liability	(14,560)
Ending balance -Redeemable Convertible Preferred Stock Liability	$ 0