Marketable Securities - Summary of unrealized gain (loss) on available-for-sale securities, net, presented in the statements of operations and comprehensive income (loss) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Investments Debt And Equity Securities [Abstract]
Unrealized gain (loss) before reclassifications	$ (2,202)	$ (426)	$ 1,392
Realized gains reclassified to investment income	(7)	(139)	(40)
Income tax expense			(467)
Unrealized gain (loss) on available-for-sale securities, net	$ (2,209)	$ (565)	$ 885