Lease - Additional Information (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Jul. 17, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Lessee Disclosure [Abstract]
Lease expiration date				Apr. 30, 2023
Lessee operating lease renewal term description				no stated renewal options
Total undiscounted lease payments	$ 400	$ 1,564		$ 1,564
Operating lease term of contract	2 years 7 months 6 days
Operating lease not yet commenced description	expected to commence during the fourth quarter of 2020
Operating lease expense		$ 200	$ 200	$ 600	$ 500