LIABILITY FOR EMPLOYEE RIGHTS UPON RETIREMENT (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Employee severance obligation payments	$ 143,000	$ 145,000	$ 166,000
Contributions	642,000	620,000	746,000
Severance expense	784,000	781,000	906,000
Net gain (loss) for the period	58,000	$ 46,000	$ 21,000
Benefits Payable During Next Five Years	246,000
Contribution to Insurance Companies [Member]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	866,000
Contribution to Defined Contribution Plans [Member]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 722,000