MARKETABLE SECURITIES (Details) - USD ($) |
Sep. 30, 2019 |
Dec. 31, 2018 |
|---|---|---|
| Fair Value [Member] | ||
| Certificates of deposit | $ 4,508,000 | $ 13,151,000 |
| Fixed income mutual funds | 15,819,000 | 9,640,000 |
| Corporate bonds and notes | 10,956,000 | 8,437,000 |
| Total marketable securities | 31,283,000 | 31,228,000 |
| Cost Basis [Member] | ||
| Certificates of deposit | 4,500,000 | 13,151,000 |
| Fixed income mutual funds | 15,810,000 | 9,648,000 |
| Corporate bonds and notes | 10,854,000 | 8,518,000 |
| Total marketable securities | 31,164,000 | 31,317,000 |
| Gross Unrealized Gains [Member] | ||
| Certificates of deposit | 8,000 | |
| Fixed income mutual funds | 9,000 | |
| Corporate bonds and notes | 176,000 | |
| Total marketable securities | 193,000 | |
| Gross Unrealized Losses [Member] | ||
| Certificates of deposit | ||
| Fixed income mutual funds | (8,000) | |
| Corporate bonds and notes | (74,000) | (81,000) |
| Total marketable securities | $ (74,000) | $ (89,000) |