INCOME TAXES (Effective Income Tax Rate Reconciliation) (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Federal income tax statutory rate	35.00%	35.00%	35.00%
Increase (decrease) in tax rate due to:
Tax-exempt interest	(2.60%)	(3.90%)	(2.60%)
Investment in life insurance	(1.20%)	(1.30%)	(0.80%)
State income taxes, net of federal tax offset	2.20%	1.10%	1.10%
Tax credits	(0.80%)	(1.60%)	(0.80%)
Merger and acquisition costs	0.00%	1.90%	0.70%
Other	1.50%	2.30%	0.70%
Effective income tax rate	34.10%	33.50%	33.30%