FAIR VALUE MEASUREMENTS - SCHEDULE OF SHORT-TERM INVESTMENTS (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Short-term investments, amortized cost	$ 32,914	$ 39,933
Short-term investments, gross unrealized holding gains	17	0
Short-term investments, gross unrealized holding losses	0	(15)
Short-term investments, fair value	32,931	39,918
U.S. Treasury securities
Schedule of Available-for-sale Securities [Line Items]
Short-term investments, amortized cost	32,914	39,933
Short-term investments, gross unrealized holding gains	17	0
Short-term investments, gross unrealized holding losses	0	(15)
Short-term investments, fair value	$ 32,931	$ 39,918