Revenues - Summary of Deferred Revenue (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Revenue From Contract With Customer [Abstract]
Beginning Balance	$ 2,759	$ 2,957
Increase	2,390	2,759
Decrease	(2,759)	(2,957)
Ending Balance	$ 2,390	$ 2,759