Summary of Unvested Restricted Stock Units (Detail) - Restricted Stock Units (RSUs)	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Beginning Balance | shares	4,000
Granted | shares	56,000
Vested | shares	(8,000)
Forfeited or cancelled | shares	(2,000)
Ending Balance | shares	50,000
Unvested RSUs at December 31, 2022 | $ / shares	$ 525.72
Granted | $ / shares	11.46
Vested | $ / shares	192.09
Forfeited or cancelled | $ / shares	116.41
Unvested RSUs as of September 30, 2023 | $ / shares	$ 19.8