Other Financial Statement Information - Schedule of Changes in the Reserve for Product Warranties (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Beginning of period	$ 804	$ 174
Additions charged to cost of revenue	741	1,685
Repairs and replacements	(1,078)	(1,055)
End of period	$ 467	$ 804