FAIR VALUE OF FINANCIAL INSTRUMENTS - Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014
Assets:
Cash and cash equivalents	$ 78,717	$ 150,183	$ 111,459	$ 154,459
Securities available for sale	298,973	283,454
Securities held to maturity	93,018	120,093
FHLB stock	4,844	3,797
Liabilities:
Short-term borrowings	22,000
Level 1
Assets:
Cash and cash equivalents	78,717	150,183
Total assets	78,717	150,183
Liabilities:
Deposits	1,294,809	1,296,867
Accrued interest payable	10	13
Total liabilities	1,294,819	1,296,880
Level 2
Assets:
Securities available for sale	298,973	283,454
Securities held to maturity	93,018	120,093
Interest rate swap agreement	2,402	1,084
Accrued interest receivable	1,017	1,085
Total assets	395,410	405,716
Liabilities:
Deposits	209,352	254,179
Short-term borrowings	22,000
Securities sold under agreement to repurchase	276,027	286,586
Other long-term debt	3,704	5,191
Junior subordinated debentures issued to unconsolidated subsidiary trust	15,536	14,975
Interest rate swap agreement	1,881	1,004
Accrued interest payable	105	139
Total liabilities	528,605	562,074
Level 3
Assets:
Loans, net of allowance for loan losses	1,469,387	1,397,877
Accrued interest receivable	2,893	3,289
Total assets	1,472,280	1,401,166
Carrying Amount
Assets:
Cash and cash equivalents	78,717	150,183
Securities available for sale	298,973	283,454
Securities held to maturity	90,672	119,674
FHLB stock	4,844	3,797
Loans, net of allowance for loan losses	1,464,745	1,402,240
Interest rate swap agreement	2,402	1,084
Accrued interest receivable	3,910	4,374
Total assets	1,944,263	1,964,806
Liabilities:
Deposits	1,503,840	1,551,439
Short-term borrowings	22,000
Securities sold under agreement to repurchase	276,083	286,639
Other long-term debt	3,673	5,238
Junior subordinated debentures issued to unconsolidated subsidiary trust	20,619	20,619
Interest rate swap agreement	1,881	1,004
Accrued interest payable	115	152
Total liabilities	1,828,211	1,865,091
Fair Value
Assets:
Cash and cash equivalents	78,717	150,183
Securities available for sale	298,973	283,454
Securities held to maturity	93,018	120,093
Loans, net of allowance for loan losses	1,469,387	1,397,877
Interest rate swap agreement	2,402	1,084
Accrued interest receivable	3,910	4,374
Total assets	1,946,407	1,957,065
Liabilities:
Deposits	1,504,161	1,551,046
Short-term borrowings	22,000
Securities sold under agreement to repurchase	276,027	286,586
Other long-term debt	3,704	5,191
Junior subordinated debentures issued to unconsolidated subsidiary trust	15,536	14,975
Interest rate swap agreement	1,881	1,004
Accrued interest payable	115	152
Total liabilities	$ 1,823,424	$ 1,858,954