STOCKHOLDERS' EQUITY - CHANGES IN ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) (Detail) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Beginning balance	$ 99
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other comprehensive income before reclassifications	5
Amounts reclassified from accumulated other comprehensive income	0
Net current period other comprehensive income	5
Ending balance	104
Unrealized Gains and Losses on Short-term Investments
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Beginning balance	(23)
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other comprehensive income before reclassifications	5
Amounts reclassified from accumulated other comprehensive income	0
Net current period other comprehensive income	5
Ending balance	(18)
Foreign Currency Items
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax [Abstract]
Beginning balance	122
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other comprehensive income before reclassifications	0
Amounts reclassified from accumulated other comprehensive income	0
Net current period other comprehensive income	0
Ending balance	$ 122