NET INCOME (LOSS) PER SHARE - Reconciliation used in Computing Basic and Diluted Net Income (Loss) per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net income (loss)	$ 5,401	$ (20,044)
Denominator:
Weighted-average common stock outstanding, basic (in shares)	28,117	31,529
Dilutive potential common shares:
Stock options, RSU's, RSAs and ESPP (in shares)	360	0
Shares used in computation of diluted net income (loss) per share (in shares)	28,477	31,529
Basic net income (loss) per share (in dollars per share)	$ 0.19	$ (0.64)
Diluted net income (loss) per share (in dollars per share)	$ 0.19	$ (0.64)