LOANS, Credit Quality By Past Due Status (Details) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Aged analysis of the company's loans [Abstract]
Total loans		$ 4,948,562	$ 4,801,375
Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		1,963	1,801
Nonaccrual		16,600	18,805
Total past due		50,545	49,612
Current		4,402,657	4,134,109
Total loans		4,453,202	4,183,721
Legacy Loan [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		31,982	29,006
Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		1,113	394
Nonaccrual		4,019	2,923
Total past due		8,439	6,246
Acquired impaired	[1]	5,553	7,299
Current		481,368	604,109
Total loans		495,360	617,654
Acquired Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		3,307	2,929
Consumer Mortgage [Member] | Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
Total loans		1,659,760	1,581,458
Consumer Mortgage [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		159,941	188,296
Business Lending [Member]
Aged analysis of the company's loans [Abstract]
Total loans		1,490,076	1,497,271
Business Lending [Member] | Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
Total loans		1,277,666	1,233,628
Business Lending [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		212,410	263,643
Consumer Indirect [Member] | Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
Total loans		1,014,825	890,339
Consumer Indirect [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		30,147	45,421
Consumer Direct [Member] | Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
Total loans		181,922	178,051
Consumer Direct [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		9,893	17,025
Home Equity [Member] | Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
Total loans		319,029	300,245
Home Equity [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		82,969	103,269
Residential Portfolio Segment [Member] | Consumer Mortgage [Member]
Aged analysis of the company's loans [Abstract]
Total loans		1,819,701	1,769,754
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		1,180	1,411
Nonaccrual		11,352	11,394
Total past due		23,911	23,287
Current		1,635,849	1,558,171
Total loans		1,659,760	1,581,458
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Legacy Loan [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		11,379	10,482
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		205	394
Nonaccrual		2,332	1,396
Total past due		4,076	3,163
Acquired impaired	[1]	0	0
Current		155,865	185,133
Total loans		159,941	188,296
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Acquired Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		1,539	1,373
Commercial Portfolio Segment [Member] | Business Lending [Member]
Aged analysis of the company's loans [Abstract]
Total loans		1,490,076	1,497,271
Commercial Portfolio Segment [Member] | Business Lending [Member] | Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		145	126
Nonaccrual		3,811	5,381
Total past due		7,877	9,949
Current		1,269,789	1,223,679
Total loans		1,277,666	1,233,628
Commercial Portfolio Segment [Member] | Business Lending [Member] | Legacy Loan [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		3,921	4,442
Commercial Portfolio Segment [Member] | Business Lending [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		0	0
Nonaccrual		1,252	1,186
Total past due		1,780	1,721
Acquired impaired	[1]	5,553	7,299
Current		205,077	254,623
Total loans		212,410	263,643
Commercial Portfolio Segment [Member] | Business Lending [Member] | Acquired Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		528	535
Consumer Portfolio Segment [Member] | Consumer Indirect [Member]
Aged analysis of the company's loans [Abstract]
Total loans		1,044,972	935,760
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		166	102
Nonaccrual		0	0
Total past due		14,049	11,677
Current		1,000,776	878,662
Total loans		1,014,825	890,339
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Legacy Loan [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		13,883	11,575
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		3	0
Nonaccrual		0	0
Total past due		234	245
Acquired impaired	[1]	0	0
Current		29,913	45,176
Total loans		30,147	45,421
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Acquired Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		231	245
Consumer Portfolio Segment [Member] | Consumer Direct [Member]
Aged analysis of the company's loans [Abstract]
Total loans		191,815	195,076
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		58	51
Nonaccrual		0	1
Total past due		1,607	1,466
Current		180,315	176,585
Total loans		181,922	178,051
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Legacy Loan [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		1,549	1,414
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		0	0
Nonaccrual		0	14
Total past due		231	154
Acquired impaired	[1]	0	0
Current		9,662	16,871
Total loans		9,893	17,025
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Acquired Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		231	140
Consumer Portfolio Segment [Member] | Home Equity [Member]
Aged analysis of the company's loans [Abstract]
Total loans		401,998	403,514
Consumer Portfolio Segment [Member] | Home Equity [Member] | Legacy Loan [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		414	111
Nonaccrual		1,437	2,029
Total past due		3,101	3,233
Current		315,928	297,012
Total loans		319,029	300,245
Consumer Portfolio Segment [Member] | Home Equity [Member] | Legacy Loan [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		1,250	1,093
Consumer Portfolio Segment [Member] | Home Equity [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		905	0
Nonaccrual		435	327
Total past due		2,118	963
Acquired impaired	[1]	0	0
Current		80,851	102,306
Total loans		82,969	103,269
Consumer Portfolio Segment [Member] | Home Equity [Member] | Acquired Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		$ 778	$ 636

[1] Acquired impaired loans were not classified as nonperforming assets as the loans are considered to be performing under ASC 310-30. As a result interest income, through the accretion of the difference between the carrying amount of the loans and the expected cashflows, is being recognized on all acquired impaired loans.