LOANS, Amount of Business Lending Loans by Credit Quality Category (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 4,821,172	$ 4,801,375
Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	4,230,303	4,183,721
Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	590,869	617,654
Business Lending [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,509,421	1,497,271
Business Lending [Member] | Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,254,998	1,233,628
Business Lending [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	254,423	263,643
Business Lending [Member] | Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,252,012	1,267,738
Business Lending [Member] | Pass [Member] | Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,049,441	1,048,364
Business Lending [Member] | Pass [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	202,571	219,374
Business Lending [Member] | Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	161,254	144,775
Business Lending [Member] | Special Mention [Member] | Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	133,939	124,768
Business Lending [Member] | Special Mention [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	27,315	20,007
Business Lending [Member] | Classified [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	88,891	77,144
Business Lending [Member] | Classified [Member] | Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	71,528	60,181
Business Lending [Member] | Classified [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	17,363	16,963
Business Lending [Member] | Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	90	315
Business Lending [Member] | Doubtful [Member] | Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	90	315
Business Lending [Member] | Doubtful [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	0
Business Lending [Member] | Acquired Impaired [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	7,174	7,299
Business Lending [Member] | Acquired Impaired [Member] | Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	0
Business Lending [Member] | Acquired Impaired [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	7,174	7,299
All Other Loans [Member] | Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	2,975,305	2,950,093
All Other Loans [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	336,446	354,011
All Other Loans [Member] | Performing [Member] | Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	2,959,886	2,934,994
All Other Loans [Member] | Performing [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	333,656	351,880
All Other Loans [Member] | Nonperforming [Member] | Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	15,419	15,099
All Other Loans [Member] | Nonperforming [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	2,790	2,131
Consumer Mortgage [Member] | Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,596,191	1,581,458
Consumer Mortgage [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	181,601	188,296
Consumer Mortgage [Member] | Performing [Member] | Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	1,583,335	1,568,653
Consumer Mortgage [Member] | Performing [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	179,375	186,506
Consumer Mortgage [Member] | Nonperforming [Member] | Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	12,856	12,805
Consumer Mortgage [Member] | Nonperforming [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	2,226	1,790
Consumer Indirect [Member] | Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	900,136	890,339
Consumer Indirect [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	41,015	45,421
Consumer Indirect [Member] | Performing [Member] | Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	899,953	890,237
Consumer Indirect [Member] | Performing [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	41,015	45,421
Consumer Indirect [Member] | Nonperforming [Member] | Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	183	102
Consumer Indirect [Member] | Nonperforming [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	0	0
Consumer Direct [Member] | Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	174,780	178,051
Consumer Direct [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	14,755	17,025
Consumer Direct [Member] | Performing [Member] | Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	174,726	177,999
Consumer Direct [Member] | Performing [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	14,736	17,011
Consumer Direct [Member] | Nonperforming [Member] | Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	54	52
Consumer Direct [Member] | Nonperforming [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	19	14
Home Equity [Member] | Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	304,198	300,245
Home Equity [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	99,075	103,269
Home Equity [Member] | Performing [Member] | Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	301,872	298,105
Home Equity [Member] | Performing [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	98,530	102,942
Home Equity [Member] | Nonperforming [Member] | Legacy Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	2,326	2,140
Home Equity [Member] | Nonperforming [Member] | Acquired Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans	$ 545	$ 327