SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2019
Accounting Policies [Abstract]
Cash equivalents maturity period	3 months
Short-term investments maturity period	90 days
Advertising expense	$ 67	$ 221	$ 102
Period of maturities, money market and highly liquid debt	90 days
Minimum | Accounting Standards Update 2016-02 | Scenario, forecast
Item Effected [Line Items]
Operating Lease, Liability				$ 4,000
Operating lease, right-of-use asset				4,000
Maximum | Accounting Standards Update 2016-02 | Scenario, forecast
Item Effected [Line Items]
Operating Lease, Liability				5,000
Operating lease, right-of-use asset				$ 5,000