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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 |

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