INCOME TAXES (Effective Income Tax Rate Reconciliation) (Details)	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Federal income tax statutory rate	21.00%	35.00%	35.00%
Increase (decrease) in tax rate due to:
Tax-exempt interest	(2.00%)	(2.60%)	(2.60%)
Investment in life insurance	(0.60%)	(1.10%)	(1.20%)
State income taxes, net of federal tax offset	2.30%	2.00%	2.20%
Tax credits	(0.80%)	(0.60%)	(0.80%)
Change in effective income tax rate due to merger and acquisition costs	0.10%	0.00%	0.00%
Merger and acquisition costs	(2.50%)	0.00%	0.00%
Increase in federal statutory income tax rate due to 2017 Tax Cuts and Jobs Act	0.00%	28.20%
Other	(0.20%)	(1.10%)	1.50%
Effective income tax rate	17.30%	59.80%	34.10%

Change in effective income tax rate due to merger and acquisition costs

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Increase (Decrease) in Taxes Due to Percentage [Abstract]

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Increase in federal statutory income tax rate due to 2017 Tax Cuts and Jobs Act

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to changes in the valuation allowance for deferred tax assets.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to tax credits. Including, but not limited to, research credit, foreign tax credit, investment tax credit, and other tax credits.

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