Basis of Presentation - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2020	Jun. 30, 2020
Basis Of Presentation [Line Items]
Accumulated losses	$ (433,252)		$ (437,440)		$ (424,036)	$ (469,762)
Net loss	$ 4,188	$ (21,826)	$ 4,900	$ 99,900