Fair value measurements - Schedule of The Reconciliation of Changes in Level 3 (Detail) - Fair Value, Inputs, Level 3 [Member] $ in Thousands	6 Months Ended
	Jun. 30, 2021 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ 47,615
Change in fair value	63,526
Cashless exercise of warrants	(111,141)
Ending Balance	$ 0