RETIREMENT FUND AND PROFIT SHARING PLAN, SERP (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 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	$ 366	$ 350
Interest cost	166	168	332	337
Net amortization	111	94	222	187
Net periodic benefit cost	460	$ 437	920	$ 874
Amounts recognized in accumulated other comprehensive loss, pretax [Abstract]
Prior service cost	1,007		1,007		$ 1,135
Net loss	3,638		3,638		3,732
Total amounts recognized in accumulated other comprehensive loss	$ 4,645		$ 4,645		$ 4,867