FAIR VALUE MEASUREMENTS - Assets Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
U.S. Government securities (1)	$ 23,724	$ 36,544
Convertible note receivable (available-for-sale debt security) (2)	2,013
Assets measured at fair value, total	106,567	120,354
Quoted Prices in Active Markets for Identical Assets (level 1)
U.S. Government securities (1)	23,724	36,544
Assets measured at fair value, total	104,554	120,354
Significant Unobservable Inputs (level 3)
Convertible note receivable (available-for-sale debt security) (2)	2,013
Assets measured at fair value, total	2,013
Money Market Mutual Funds
Cash equivalents	80,830	83,810
Money Market Mutual Funds | Quoted Prices in Active Markets for Identical Assets (level 1)
Cash equivalents	$ 80,830	$ 83,810