FAIR VALUE OF FINANCIAL INSTRUMENTS (Details) - USD ($) | Sep. 30, 2021 | Dec. 31, 2020 |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | | |
Cash and Cash Equivalents, Fair Value Disclosure | $ 6,589,000 | $ 7,802,000 |
Fair Value, Inputs, Level 1 [Member] | | |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | | |
Cash and Cash Equivalents, Fair Value Disclosure | 5,996,000 | 7,189,000 |
Fair Value, Inputs, Level 2 [Member] | | |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | | |
Cash and Cash Equivalents, Fair Value Disclosure | 593,000 | 613,000 |
Fair Value, Inputs, Level 3 [Member] | | |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | | |
Cash and Cash Equivalents, Fair Value Disclosure | 0 | 0 |
Money Market Mutual Funds [Member] | | |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | | |
Cash and Cash Equivalents, Fair Value Disclosure | 1,874,000 | 1,496,000 |
Money Market Mutual Funds [Member] | Fair Value, Inputs, Level 1 [Member] | | |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | | |
Cash and Cash Equivalents, Fair Value Disclosure | 1,874,000 | 1,496,000 |
Money Market Mutual Funds [Member] | Fair Value, Inputs, Level 2 [Member] | | |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | | |
Cash and Cash Equivalents, Fair Value Disclosure | 0 | 0 |
Money Market Mutual Funds [Member] | Fair Value, Inputs, Level 3 [Member] | | |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | | |
Cash and Cash Equivalents, Fair Value Disclosure | 0 | 0 |
US T-Bills [Member] | | |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | | |
Cash and Cash Equivalents, Fair Value Disclosure | 1,900,000 | 2,900,000 |
US T-Bills [Member] | Fair Value, Inputs, Level 1 [Member] | | |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | | |
Cash and Cash Equivalents, Fair Value Disclosure | 1,900,000 | 2,900,000 |
US T-Bills [Member] | Fair Value, Inputs, Level 2 [Member] | | |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | | |
Cash and Cash Equivalents, Fair Value Disclosure | | |
US T-Bills [Member] | Fair Value, Inputs, Level 3 [Member] | | |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | | |
Cash and Cash Equivalents, Fair Value Disclosure | | |
Corporate Debt Securities [Member] | | |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | | |
Cash and Cash Equivalents, Fair Value Disclosure | 593,000 | 613,000 |
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member] | | |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | | |
Cash and Cash Equivalents, Fair Value Disclosure | 0 | 0 |
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | | |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | | |
Cash and Cash Equivalents, Fair Value Disclosure | 593,000 | 613,000 |
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member] | | |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | | |
Cash and Cash Equivalents, Fair Value Disclosure | 0 | 0 |
Marketable Equity Securities [Member] | | |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | | |
Cash and Cash Equivalents, Fair Value Disclosure | 2,222,000 | 2,793,000 |
Marketable Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member] | | |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | | |
Cash and Cash Equivalents, Fair Value Disclosure | 2,222,000 | 2,793,000 |
Marketable Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member] | | |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | | |
Cash and Cash Equivalents, Fair Value Disclosure | 0 | 0 |
Marketable Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member] | | |
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | | |
Cash and Cash Equivalents, Fair Value Disclosure | $ 0 | $ 0 |