RETIREMENT FUND AND PROFIT SHARING PLAN, SERP (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Type [Extensible List]	us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember		us-gaap:SupplementalEmployeeRetirementPlanDefinedBenefitMember
SERP [Member]
Components of SERP expense [Abstract]
Service cost	$ 183	$ 175	$ 549	$ 525
Interest cost	166	168	498	505
Net amortization	111	94	332	281
Net periodic benefit cost	460	$ 437	1,379	$ 1,311
Amounts recognized in accumulated other comprehensive loss, net of tax [Abstract]
Prior service cost	943		943		$ 1,135
Net loss	3,591		3,591		3,732
Total amounts recognized in accumulated other comprehensive loss	$ 4,534		$ 4,534		$ 4,867