Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Mar. 27, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2013
Income Taxes [Line Items]
Net operating loss carryforwards		$ 147,004	$ 124,115
Deferred tax assets operating loss carryforwards without expire date		220,000
Research and development credit carryforwards		$ 37,183	35,130
Net operating loss carryforwards, expiration date		2040
Uncertain Tax Positions Adjustment		$ 0	$ 0	$ 0
Increase (decrease) in deferred tax assets		18,800
Covid 19
Income Taxes [Line Items]
Relaxation of taxable income, percentage	30.00%
Relaxation of Adjusted taxable income, percentage	50.00%
Covid 19 | Qualified Improvement Property
Income Taxes [Line Items]
Eligible bonus percentage	100.00%
Estimated useful life	15
Research Tax Credit Carryforward
Income Taxes [Line Items]
Research and development credit carryforwards		37,000
Net Operating Loss Carryforwards
Income Taxes [Line Items]
Increase (decrease) in deferred tax assets					$ (11,200)
General Business Credits
Income Taxes [Line Items]
Increase (decrease) in deferred tax assets					$ (636)
Domestic Tax Authority
Income Taxes [Line Items]
Net operating loss carryforwards		$ 562,000
Net operating loss carryforwards, expiration date		2037
Federal and State
Income Taxes [Line Items]
Deferred tax assets operating loss carryforwards with expire date		$ 342,000
State and Local Jurisdiction
Income Taxes [Line Items]
Net operating loss carryforwards		$ 458,000