STOCK COMPENSATION PLANS (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2016 USD ($) Director $ / shares shares	Mar. 31, 2015 USD ($)	Dec. 31, 2014	Dec. 18, 2015 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized expense related to non-vested option shares | $	$ 0
Number of directors in committee | Director	3
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Granted, option shares (in shares)	0
Expired, option shares (in shares)	0
Shares of Class A Non-Voting Common Stock under option [Abstract]
Vesting period for granted option (in years)	1 year
Options granted term (in years)	10 years
Weighted-average assumptions used for grants issued [Abstract]
Expected Dividend Yield (in hundredths)			3.88%
Expected Stock Price Volatility (in hundredths)			26.50%
Weighted Average Risk-Free Interest Rate (in hundredths)			2.24%
Weighted Average Expected Life of Options (in years)			7 years 6 months 7 days
Class A Stock [Member] | 2005 Equity Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense | $		$ 33,000
Class A Stock [Member] | 2015 Equity Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorizes for new issues				5,000
Compensation expense | $	$ 0
Number of shares authorizes under the plan (in shares)				5,000
Fair market value | $ / shares				$ 27.38
Class A Stock [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at beginning of period, option shares (in shares)	270,000
Granted, option shares (in shares)	0
Exercised, option shares (in shares)	(6,750)
Expired, option shares (in shares)	0
Outstanding at end of period, option shares (in shares)	263,250
Options exercisable at end of period, option share (in shares)	263,250
Shares of Class A Non-Voting Common Stock under option [Abstract]
Outstanding at beginning of period, weighted average exercise price (in dollars per shares) | $ / shares	$ 19.34
Granted, weighted average exercise price (in dollars per shares) | $ / shares	0
Exercised, weighted average exercise price (in dollars per shares) | $ / shares	21.11
Outstanding at end of period, weighted average exercise price (in dollars per shares) | $ / shares	19.30
Options exercisable at end of period, weighted average exercise price (in dollars per shares) | $ / shares	$ 19.30
Outstanding at end of period, weighted average remaining life (in years)	4 years 8 months 16 days
Options exercisable at end of period, weighted average remaining life (in years)	4 years 8 months 16 days
Options exercisable at beginning of period, aggregate intrinsic value | $	$ 2,256,000
Exercised, aggregate intrinsic value | $	30,000
Outstanding at end of period, aggregate intrinsic value | $	2,280
Options exercisable at end of period, aggregate intrinsic value | $	$ 2,280,000