Income Tax - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Nov. 01, 2013
Operating Loss Carryforwards [Line Items]
Provision for income taxes	$ 8,255	$ 218	$ 87
Change in valuation allowance	120,400	10,800
Operating loss carryforwards, limitation amount				$ 4,800
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	373,700	$ 258,800
Tax credit carryforward	27,600
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	188,500
Tax credit carryforward	$ 20,900