LOANS - Categorized by Class and Internally Assigned Risk Grades (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Loans by class categorized by internally assigned risk grades
Total loans	$ 3,422,582	$ 3,268,772
Pass
Loans by class categorized by internally assigned risk grades
Total loans	3,348,413	3,180,905
Special Mention
Loans by class categorized by internally assigned risk grades
Total loans	33,616	43,186
Substandard
Loans by class categorized by internally assigned risk grades
Total loans	40,553	44,681
Doubtful
Loans by class categorized by internally assigned risk grades
Total loans	0	0
Commercial Real Estate | Mortgage loans
Loans by class categorized by internally assigned risk grades
Total loans	1,436,221	1,373,556
Commercial Real Estate | Mortgage loans | Owner occupied
Loans by class categorized by internally assigned risk grades
Total loans	525,329	510,398
Commercial Real Estate | Mortgage loans | Owner occupied | Pass
Loans by class categorized by internally assigned risk grades
Total loans	512,123	480,503
Commercial Real Estate | Mortgage loans | Owner occupied | Special Mention
Loans by class categorized by internally assigned risk grades
Total loans	11,596	12,045
Commercial Real Estate | Mortgage loans | Owner occupied | Substandard
Loans by class categorized by internally assigned risk grades
Total loans	1,610	17,850
Commercial Real Estate | Mortgage loans | Owner occupied | Doubtful
Loans by class categorized by internally assigned risk grades
Total loans	0	0
Commercial Real Estate | Mortgage loans | Non-owner occupied
Loans by class categorized by internally assigned risk grades
Total loans	910,892	863,158
Commercial Real Estate | Mortgage loans | Non-owner occupied | Pass
Loans by class categorized by internally assigned risk grades
Total loans	896,654	858,069
Commercial Real Estate | Mortgage loans | Non-owner occupied | Special Mention
Loans by class categorized by internally assigned risk grades
Total loans	735	2,188
Commercial Real Estate | Mortgage loans | Non-owner occupied | Substandard
Loans by class categorized by internally assigned risk grades
Total loans	13,503	2,901
Commercial Real Estate | Mortgage loans | Non-owner occupied | Doubtful
Loans by class categorized by internally assigned risk grades
Total loans	0	0
Multi-family | Mortgage loans
Loans by class categorized by internally assigned risk grades
Total loans	631,146	585,827
Multi-family | Mortgage loans | Pass
Loans by class categorized by internally assigned risk grades
Total loans	630,735	585,409
Multi-family | Mortgage loans | Special Mention
Loans by class categorized by internally assigned risk grades
Total loans	411	418
Multi-family | Mortgage loans | Substandard
Loans by class categorized by internally assigned risk grades
Total loans	0	0
Multi-family | Mortgage loans | Doubtful
Loans by class categorized by internally assigned risk grades
Total loans	0	0
Residential real estate mortgage loans | Mortgage loans
Loans by class categorized by internally assigned risk grades
Total loans	503,354	519,763
Residential real estate mortgage loans | Mortgage loans | Residential mortgage
Loans by class categorized by internally assigned risk grades
Total loans	435,386	448,515
Residential real estate mortgage loans | Mortgage loans | Residential mortgage | Pass
Loans by class categorized by internally assigned risk grades
Total loans	425,836	438,891
Residential real estate mortgage loans | Mortgage loans | Residential mortgage | Special Mention
Loans by class categorized by internally assigned risk grades
Total loans	8,255	8,510
Residential real estate mortgage loans | Mortgage loans | Residential mortgage | Substandard
Loans by class categorized by internally assigned risk grades
Total loans	1,295	1,114
Residential real estate mortgage loans | Mortgage loans | Residential mortgage | Doubtful
Loans by class categorized by internally assigned risk grades
Total loans	0	0
Residential real estate mortgage loans | Mortgage loans | Home equity
Loans by class categorized by internally assigned risk grades
Total loans	67,968	71,248
Residential real estate mortgage loans | Mortgage loans | Home equity | Pass
Loans by class categorized by internally assigned risk grades
Total loans	66,469	68,480
Residential real estate mortgage loans | Mortgage loans | Home equity | Special Mention
Loans by class categorized by internally assigned risk grades
Total loans	681	1,594
Residential real estate mortgage loans | Mortgage loans | Home equity | Substandard
Loans by class categorized by internally assigned risk grades
Total loans	818	1,174
Residential real estate mortgage loans | Mortgage loans | Home equity | Doubtful
Loans by class categorized by internally assigned risk grades
Total loans	0	0
Commercial, industrial and agricultural loans
Loans by class categorized by internally assigned risk grades
Total loans	675,168	645,724
Commercial, industrial and agricultural loans | Secured
Loans by class categorized by internally assigned risk grades
Total loans	164,950	168,540
Commercial, industrial and agricultural loans | Secured | Pass
Loans by class categorized by internally assigned risk grades
Total loans	153,055	147,474
Commercial, industrial and agricultural loans | Secured | Special Mention
Loans by class categorized by internally assigned risk grades
Total loans	2,009	5,536
Commercial, industrial and agricultural loans | Secured | Substandard
Loans by class categorized by internally assigned risk grades
Total loans	9,886	15,530
Commercial, industrial and agricultural loans | Secured | Doubtful
Loans by class categorized by internally assigned risk grades
Total loans	0	0
Commercial, industrial and agricultural loans | Unsecured
Loans by class categorized by internally assigned risk grades
Total loans	510,218	477,184
Commercial, industrial and agricultural loans | Unsecured | Pass
Loans by class categorized by internally assigned risk grades
Total loans	487,922	458,526
Commercial, industrial and agricultural loans | Unsecured | Special Mention
Loans by class categorized by internally assigned risk grades
Total loans	9,923	12,886
Commercial, industrial and agricultural loans | Unsecured | Substandard
Loans by class categorized by internally assigned risk grades
Total loans	12,373	5,772
Commercial, industrial and agricultural loans | Unsecured | Doubtful
Loans by class categorized by internally assigned risk grades
Total loans	0	0
Real estate construction and land loans
Loans by class categorized by internally assigned risk grades
Total loans	150,868	123,393
Real estate construction and land loans | Pass
Loans by class categorized by internally assigned risk grades
Total loans	150,572	123,089
Real estate construction and land loans | Special Mention
Loans by class categorized by internally assigned risk grades
Total loans	0	0
Real estate construction and land loans | Substandard
Loans by class categorized by internally assigned risk grades
Total loans	296	304
Real estate construction and land loans | Doubtful
Loans by class categorized by internally assigned risk grades
Total loans	0	0
Installment/consumer loans
Loans by class categorized by internally assigned risk grades
Total loans	25,825	20,509
Installment/consumer loans | Pass
Loans by class categorized by internally assigned risk grades
Total loans	25,047	20,464
Installment/consumer loans | Special Mention
Loans by class categorized by internally assigned risk grades
Total loans	6	9
Installment/consumer loans | Substandard
Loans by class categorized by internally assigned risk grades
Total loans	772	36
Installment/consumer loans | Doubtful
Loans by class categorized by internally assigned risk grades
Total loans	$ 0	$ 0