Fair Value Measurement - Summary of Opening Balances of Assets and Liabilities Categorized Within Level 3 of the Fair Value Hierarchy Measured at Fair Value on a Recurring Basis (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($)
Fair Value Disclosures [Abstract]
Debt securities classified as available-for-sale, Beginning Balance	$ 2,500
Debt securities classified as available-for-sale, Settlements	(2,500)
Warrant liability, Beginning Balance	(120,647)
Warrant liability, Settlements	81,223
Warrant liability, Change in fair value	(83,380)
Warrant liability, Ending Balance	$ (122,804)