ALLOWANCE FOR LOAN LOSSES AND CREDIT QUALITY (Allowance for loan losses by portfolio segment) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	$ 43,774	$ 43,284	$ 43,718	$ 43,610
Provision for loan losses	500	0	(700)	0
Loans charged-off	(261)	(297)	(764)	(762)
Recoveries	550	260	909	399
Net (charge-offs)/recoveries	289	(37)	145	(363)
Ending balance	44,563	43,247	44,563	43,247
Commercial and Industrial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	19,781	20,465	20,272	21,564
Provision for loan losses	160	605	(179)	(342)
Loans charged-off	(11)	(160)	(386)	(374)
Recoveries	289	25	512	87
Net (charge-offs)/recoveries	278	(135)	126	(287)
Ending balance	20,219	20,935	20,219	20,935
Commercial Real Estate and Multi-Family Residential Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	13,718	12,752	13,452	12,473
Provision for loan losses	61	(315)	318	121
Loans charged-off	(211)	0	(259)	(168)
Recoveries	207	200	264	211
Net (charge-offs)/recoveries	(4)	200	5	43
Ending balance	13,775	12,637	13,775	12,637
Agri-business and Agricultural Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	3,459	2,454	3,532	2,445
Provision for loan losses	405	589	328	593
Loans charged-off	0	0	0	0
Recoveries	6	4	10	9
Net (charge-offs)/recoveries	6	4	10	9
Ending balance	3,870	3,047	3,870	3,047
Other Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	545	559	461	574
Provision for loan losses	23	(194)	107	(209)
Loans charged-off	0	0	0	0
Recoveries	0	0	0	0
Net (charge-offs)/recoveries	0	0	0	0
Ending balance	568	365	568	365
Consumer 1-4 Family Mortgage Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	2,790	3,586	2,827	3,395
Provision for loan losses	(123)	(563)	(200)	(367)
Loans charged-off	(6)	(92)	(13)	(130)
Recoveries	28	3	75	36
Net (charge-offs)/recoveries	22	(89)	62	(94)
Ending balance	2,689	2,934	2,689	2,934
Other Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	379	344	387	319
Provision for loan losses	23	6	60	48
Loans charged-off	(33)	(45)	(106)	(90)
Recoveries	20	28	48	56
Net (charge-offs)/recoveries	(13)	(17)	(58)	(34)
Ending balance	389	333	389	333
Unallocated [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Beginning balance	3,102	3,124	2,787	2,840
Provision for loan losses	(49)	(128)	266	156
Loans charged-off	0	0	0	0
Recoveries	0	0	0	0
Net (charge-offs)/recoveries	0	0	0	0
Ending balance	$ 3,053	$ 2,996	$ 3,053	$ 2,996