INVESTMENTS - By contractual maturity (Details) - USD ($) $ in Thousands |
Dec. 31, 2021 |
Dec. 31, 2020 |
|---|---|---|
| INVESTMENTS | ||
| Due in one year or less - Cost | $ 27,042 | $ 39,475 |
| Due in on year or less - Gross Unrealized Gains | 1 | 11 |
| Due in one through two years - Gross Unrealized Losses | (108) | (123) |
| Due in one year or less - Estimated Fair Value | 26,935 | 39,363 |
| Cost | 27,042 | 39,475 |
| Gross Unrealized Gains | 1 | 11 |
| Gross Unrealized Losses | (108) | (123) |
| Estimated Fair Value | $ 26,935 | $ 39,363 |