MARKETABLE SECURITIES - Marketable Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Fair value	$ 24,211	$ 16,680
Israeli mutual funds
Debt Securities, Available-for-sale [Line Items]
Fair value	1,024	1,020
Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Fair value		151
U.S. Government and agency bonds
Debt Securities, Available-for-sale [Line Items]
Fair value	3,025	6,031
U.S Treasury bills
Debt Securities, Available-for-sale [Line Items]
Fair value	1,001	$ 9,478
Corporate notes
Debt Securities, Available-for-sale [Line Items]
Fair value	14,067
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Fair value	$ 5,094