BORROWINGS (Additional Information) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Residential real estate loans and securities pledged as collateral for FHLB advances, carrying value	$ 412,900	$ 370,000
FHLB Stock owned	10,400
FHLB borrowing capacity, authorized	800,000
Line of Credit Facility, Current Borrowing Capacity	85,600
Commercial loans pledged as collateral for Federal Reserve Discount Window, carrying value	381,500	282,100
Federal Reserve borrowing capacity	286,500
Secured Debt	170,000
Securities Sold under Agreements to Repurchase	75,555	70,652	$ 50,045
Line of Credit Facility, Remaining Borrowing Capacity	325,000
American Financial Exchange [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Remaining Borrowing Capacity	119,000
Collateralized Mortgage Backed Securities [Member]
Debt Instrument [Line Items]
Securities Sold under Agreements to Repurchase	$ 100,700	$ 98,000