EMPLOYEE BENEFIT PLANS, Restricted Stock Plan (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Additional General Disclosures [Abstract]
Share-based compensation expense	$ 473,000	$ 369,000	$ 308,000
Restricted Stock [Member]
Deferred Compensation Arrangements [Abstract]
Number of shares authorized (in shares)	150,000
Number of shares available for grant (in shares)	124,051
Unvested Shares [Roll Forward]
Outstanding, beginning of year (in shares)	10,877
Granted (in shares)	5,160
Forfeited (in shares)	(337)
Vested (in shares)	(5,498)
Outstanding, end of year (in shares)	10,202	10,877
Weighted Average Market Price [Roll Forward]
Outstanding, beginning of year (in dollars per share)	$ 60.11
Granted (in dollars per share)	50.89	$ 60.02	$ 62.74
Forfeited (in dollars per share)	57.43
Vested (in dollars per share)	59.37
Outstanding, end of year (in dollars per share)	$ 55.93	$ 60.11
Additional General Disclosures [Abstract]
Share-based compensation expense	$ 333,000	$ 299,000	$ 256,000
Compensation cost related to nonvested awards that has not yet recognized	$ 571,000
Period over which compensation cost is expected to be recognized	3 years