Fair Value Disclosures - Summary of Financial Instruments Measured At Fair Value On a Recurring Basis (Detail) - Fair Value, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets
Assets measured at fair value	$ 5,764	$ 12,257
Liabilities
Liabilities measured at fair value	24,886	81,255
Level 1 [Member]
Assets
Assets measured at fair value	5,764	12,257
Level 3 [Member]
Liabilities
Liabilities measured at fair value	24,886	81,255
Derivative Liability [Member]
Liabilities
Liabilities measured at fair value		38,400
Derivative Liability [Member] | Level 3 [Member]
Liabilities
Liabilities measured at fair value		38,400
Warrant Liability [Member]
Liabilities
Liabilities measured at fair value		19,700
Warrant Liability [Member] | Level 3 [Member]
Liabilities
Liabilities measured at fair value		19,700
Acquisition Related Liabilities [Member]
Liabilities
Liabilities measured at fair value	24,886	23,155
Acquisition Related Liabilities [Member] | Level 3 [Member]
Liabilities
Liabilities measured at fair value	24,886	23,155
Cash and Cash Equivalents [Member]
Assets
Assets measured at fair value	5,764	12,257
Cash and Cash Equivalents [Member] | Level 1 [Member]
Assets
Assets measured at fair value	$ 5,764	$ 12,257