Share-Based Payment Awards - Employee Stock Purchase Plan - Additional Information (Detail) - USD ($)		3 Months Ended
	Jun. 25, 2019	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Class Of Stock [Line Items]
Employee stock purchase plan		$ 173,000	$ 187,000
Common stock, shares issued		28,741,475		18,139,981
Employee Stock Purchase Plan [Member]
Class Of Stock [Line Items]
Number of common stock, authorized for issuance	110,000
Price of common stock purchased twice a year under ESPP, percent	85.00%
Employee stock purchase plan	$ 25,000
Employee stock purchase plan, shares	5,000
Consecutive six month offering period	Aug. 01, 2019
Common stock, shares issued		27,713