Revenues - Summary of Deferred Revenue (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue From Contract With Customer [Abstract]
Beginning Balance	$ 2,390	$ 2,759
Increase	3,127	2,390
Decrease	(2,390)	(2,759)
Ending Balance	$ 3,127	$ 2,390