Income Taxes - Summary of Deferred Tax Assets and Liabilities (Detail) - TRS [Member] - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Income Tax Expense Benefit [Line Items]
Deferred tax assets	$ 32,651	$ 28,380
Deferred tax liabilities	(170)	(53)
Valuation allowance	(32,481)	(28,327)
Net deferred tax asset	$ 0	$ 0