MARKETABLE SECURITIES (Details) - USD ($) |
Mar. 31, 2020 |
Dec. 31, 2019 |
|---|---|---|
| Fair Value [Member] | ||
| Certificates of deposit | $ 10,510,000 | $ 8,959,000 |
| Fixed income mutual funds | 3,314,000 | 7,879,000 |
| Corporate bonds and notes | 4,585,000 | 8,892,000 |
| Total marketable securities | 18,409,000 | 25,730,000 |
| Cost Basis [Member] | ||
| Certificates of deposit | 10,485,000 | 8,953,000 |
| Fixed income mutual funds | 3,560,000 | 7,878,000 |
| Corporate bonds and notes | 4,689,000 | 8,813,000 |
| Total marketable securities | 18,734,000 | 25,644,000 |
| Gross Unrealized Gains [Member] | ||
| Certificates of deposit | 25,000 | 6,000 |
| Fixed income mutual funds | 1,000 | |
| Corporate bonds and notes | 112,000 | |
| Total marketable securities | 25,000 | 119,000 |
| Gross Unrealized Losses [Member] | ||
| Certificates of deposit | ||
| Fixed income mutual funds | (246,000) | |
| Corporate bonds and notes | (104,000) | (33,000) |
| Total marketable securities | $ (350,000) | $ (33,000) |