STOCK COMPENSATION PLANS (Details)					12 Months Ended
	May 08, 2019 $ / shares shares	May 02, 2018 $ / shares shares	Jun. 28, 2017 $ / shares shares	May 03, 2017 $ / shares shares	Dec. 31, 2019 USD ($) Director $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares	Dec. 31, 2017 USD ($) $ / shares shares
Stock Compensation Plans [Abstract]
Number of directors in committee | Director					3
Shares [Abstract]
Granted (in shares) | shares					0	0	0
Weighted Average Exercise [Abstract]
Total intrinsic value of options exercised | $					$ 334,000	$ 176,000	$ 1,198,000
Received cash from the exercise of options | $					266,000
Tax benefit realized during the period | $					526,000
Unrecognized expense related to non-vested option shares | $					63,000
Weighted Average Exercise Price [Abstract]
Intrinsic value of awards | $					$ 179,500
$18.61 - $19.06 [Member] | Employee and Director [Member]
Options Outstanding [Abstract]
Range of Exercise Price, Minimum (in dollars per shares)					$ 18.61
Range of Exercise Price, Maximum (in dollars per shares)					$ 19.06
Shares Outstanding (in shares) | shares					85,750
Weighted Average Remaining Life					1 year 6 months 18 days
Weighted Average Exercise Price (in dollars per shares)					$ 18.94
Aggregate Intrinsic Value | $					$ 1,566,263
Options Exercisable [Abstract]
Range of Exercise Price, Minimum (in dollars per shares)					$ 18.61
Range of Exercise Price, Maximum (in dollars per shares)					$ 19.06
Shares Exercisable (in shares) | shares					85,750
Weighted Average Remaining Life					1 year 6 months 18 days
Weighted Average Exercise Price (in dollars per shares)					$ 18.94
Aggregate Intrinsic Value | $					$ 1,566,263
$21.86 - $22.66 [Member] | Employee and Director [Member]
Options Outstanding [Abstract]
Range of Exercise Price, Minimum (in dollars per shares)					$ 21.86
Range of Exercise Price, Maximum (in dollars per shares)					$ 22.66
Shares Outstanding (in shares) | shares					67,500
Weighted Average Remaining Life					3 years 10 months 6 days
Weighted Average Exercise Price (in dollars per shares)					$ 22.26
Aggregate Intrinsic Value | $					$ 1,009,125
Options Exercisable [Abstract]
Range of Exercise Price, Minimum (in dollars per shares)					$ 21.86
Range of Exercise Price, Maximum (in dollars per shares)					$ 22.66
Shares Exercisable (in shares) | shares					67,500
Weighted Average Remaining Life					3 years 10 months 6 days
Weighted Average Exercise Price (in dollars per shares)					$ 22.26
Aggregate Intrinsic Value | $					$ 1,009,125
Non-vested Option [Member]
Weighted Average Exercise [Abstract]
Unrecognized expense related to non-vested option shares | $					0
Restricted Stock Awards [Member] | 2015 Equity Compensation Plan [Member]
Weighted Average Exercise [Abstract]
Unrecognized expense related to non-vested option shares | $					$ 63,100
Weighted Average Exercise Price [Abstract]
Award vesting period					4 months 10 days
Class A Stock [Member] | Stock Options [Member]
Shares [Abstract]
Outstanding at beginning of year (in shares) | shares					168,750	176,802	231,755
Granted (in shares) | shares					0	0	0
Exercised/vested and released, option shares (in shares) | shares					(15,500)	(8,052)	(54,953)
Expired (in shares) | shares					0	0	0
Outstanding at end of year (in shares) | shares					153,250	168,750	176,802
Options exercisable at year end (in shares) | shares					153,250	168,750	176,802
Weighted Average Exercise [Abstract]
Outstanding at beginning of year (in dollars per shares)					$ 20.11	$ 19.91	$ 19.32
Granted, weighted average exercise price (in dollars per share)					0	0	0
Exercised/vested and released, weighted average exercise price (in dollars per shares)					17.15	15.77	17.42
Expired/cancelled, weighted average exercise price (in dollars per share)					0	0	0
Outstanding at end of year (in dollars per shares)					20.40	20.11	19.91
Options exercisable at year end (in dollars per shares)					$ 20.40	$ 20.11	$ 19.91
Class A Stock [Member] | Restricted Stock Awards [Member]
Shares [Roll Forward]
Outstanding at beginning of year (in shares) | shares					5,000	5,000	5,000
Granted (in shares) | shares	5,000	5,000	6,568	5,000	5,000	5,000	11,568
Vested/Released (in shares) | shares					(5,000)	(5,000)	(11,568)
Cancelled (in shares) | shares					0	0	0
Unvested Outstanding at end of year (in shares) | shares					5,000	5,000	5,000
Weighted Average Grant Date Fair Value [Abstract]
Outstanding at beginning of year (in dollars per shares)					$ 38.51	$ 38.10
Granted (in dollars per shares)					36.11	38.51
Vested/Released (in dollars per shares)					38.51	38.10
Cancelled (in dollars per shares)					0	0
Unvested Outstanding at end of year (in dollars per shares)					$ 36.11	38.51	$ 38.10
Weighted Average Exercise Price [Abstract]
Outstanding at beginning of year (in dollars per shares)						$ 38.10	27.70
Granted (in dollars per shares)							38.08
Vested/Released (in dollars per shares)							33.58
Cancelled (in dollars per shares)							0
Unvested Outstanding at end of year (in dollars per shares)							$ 38.10
Fair market value (in dollars per share)	$ 36.11	$ 38.51	$ 38.06	$ 38.10
Award vesting period					1 year