Reconciliation of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Balance of gross unrecognized tax benefits, beginning of period	$ 2,852	$ 1,806
Gross amounts of increases in unrecognized tax benefits as a result of tax positions taken in the current period	602	1,062
Gross amounts of decreases in unrecognized tax benefits as a result of tax positions taken in the prior period	(16)
Gross amounts of decrease due to release	(16)	(16)
Balance of gross unrecognized tax benefits, end of period	$ 3,422	$ 2,852