FAIR VALUE MEASUREMENTS - SUMMARY OF FINANCIAL INSTRUMENTSOF COMPANY AT FAIR VALUE BASED ON VALUATION APPROACH APPLIED TO EACH CLASS OF SECURITY (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Cash and Cash Equivalents [Abstract]
Money market funds	$ 81,541	$ 44,499
Total assets	81,541	44,499
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Cash and Cash Equivalents [Abstract]
Money market funds	81,541	44,499
Total assets	81,541	44,499
Significant Other Observable Inputs (Level 2) [Member]
Cash and Cash Equivalents [Abstract]
Money market funds	0	0
Total assets	0	0
Significant Unobservable Inputs (Level 3) [Member]
Cash and Cash Equivalents [Abstract]
Money market funds	0	0
Total assets	$ 0	$ 0