FAIR VALUE MEASUREMENTS (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands |
Mar. 31, 2019 |
Dec. 31, 2018 |
---|---|---|
Level 1 [Member] | Money Market Funds [Member] | ||
Fair value of assets | $ 3,050 | $ 1,767 |
Level 2 [Member] | Short-term corporate bonds [Member] | ||
Fair value of assets | 101,734 | 110,385 |
Level 2 [Member] | Short-term governmental bonds [Member] | ||
Fair value of assets | 5,330 | 8,295 |
Level 2 [Member] | Long-term corporate bonds [Member] | ||
Fair value of assets | 57,252 | 74,256 |
Level 2 [Member] | Long-term governmental bonds [Member] | ||
Fair value of assets | ||
Level 3 [Member] | Long-term Earn-out provision [Member] | ||
Fair value of liabilities | $ (1,045) | $ (332) |