RETIREMENT FUND AND PROFIT SHARING PLAN, SERP (Details) - SERP [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan, Additional Information [Abstract]
Pension expense	$ 1.8	$ 1.7
Normal retirement age	65 years
Number of years of service	20 years
Number of years of plan participation	5 years
Percentage of average base compensation payable as normal retirement benefit under the plan	40.00%
Early retirement age	55 years
Number of consecutive calendar years of plan participation to calculate average base compensation	20 years
Number of monthly payments under the death benefit of the plan	120 months
Period for which beneficiary is entitled to receive benefit	shorter of (i) the time necessary to complete 120 monthly payments or (ii) 60 months
Percentage of participant's annual base salary received by beneficiary for one year from date of death	100.00%
Period for which beneficiary will receive hundred percent annual base salary	1 year
Percentage of participant's annual base salary received by beneficiary for years two through five following date of death	50.00%
Period for which beneficiary will receive fifty percent annual base salary	4 years
Minimum [Member]
Defined Benefit Plan, Additional Information [Abstract]
Number of monthly payments entitled to beneficiary in case participant dies prior to receiving one hundred twenty monthly payments	60 months