RETIREMENT FUND AND PROFIT SHARING PLAN (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Class A Common Stock [Member]
Defined Contribution Plan Disclosure [Line Items]
Shares owned by plan (in shares)	42,642		42,642
Class B Common Stock [Member]
Defined Contribution Plan Disclosure [Line Items]
Shares owned by plan (in shares)	145,524		145,524
Retirement Fund [Member]
Defined Contribution Plan Disclosure [Line Items]
Compensation expense	$ 300	$ 300	$ 600	$ 600
Retirement Fund [Member] | Class A Common Stock [Member]
Defined Contribution Plan Disclosure [Line Items]
Shares owned by plan (in shares)	3,323		3,323
Retirement Fund [Member] | Class B Common Stock [Member]
Defined Contribution Plan Disclosure [Line Items]
Shares owned by plan (in shares)	17,342		17,342
401K Plan [Member]
Defined Contribution Plan Disclosure [Line Items]
Compensation expense	$ 100	100	$ 200	100
SERP [Member]
Components of SERP expense [Abstract]
Service cost	175	148	350	296
Interest cost	168	165	337	330
Net amortization	94	98	187	196
Net periodic benefit cost	437	$ 411	874	$ 822
Amounts recognized in accumulated other comprehensive loss, pretax [Abstract]
Prior service cost	1,055		1,055		$ 1,172
Net loss	2,900		2,900		2,970
Total amounts recognized in accumulated other comprehensive loss	$ 3,955		$ 3,955		$ 4,142