FAIR VALUE INSTRUMENTS (Tables)

12 Months Ended

Dec. 31, 2020

Fair Value Disclosures [Abstract]

Fair Value, by Balance Sheet Grouping [Table Text Block]

For the years ended December 31, 2020 and 2019, there were no major assets or liabilities measured at fair value on a recurring basis which uses significant unobservable inputs (Level 3):

	Fair value measurement at reporting date using
Description	Total December 31, 2020		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents:
Money market mutual funds	$	1,496,000	$	1,496,000	$	—	$	—
US T-bills		2,900,000		2,900,000		—		—
Marketable securities:
Corporate debt securities		613,000		—		613,000		—
Marketable equity securities		2,793,000		2,793,000		—		—
Total assets	$	7,802,000	$	7,189,000	$	613,000	$	—

	Fair value measurement at reporting date using
Description	Total December 31, 2019		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents:
Money market mutual funds	$	606,000	$	606,000	$	—	$	—
US T-bills		14,130,000		14,130,000		—
Marketable securities:
Corporate debt securities		474,000		—		474,000		—
Marketable equity securities		2,999,000		2,999,000		—		—
Total assets	$	18,209,000	$	17,735,000	$	474,000	$	—