LOANS, Credit Quality By Past Due Status (Details) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015
Aged analysis of the company's loans [Abstract]
Total loans		$ 4,940,621	$ 4,801,375
Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		1,869	1,801
Nonaccrual		16,966	18,805
Total past due		44,682	49,612
Current		4,362,404	4,134,109
Total loans		4,407,086	4,183,721
Legacy Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		25,847	29,006
Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		146	394
Nonaccrual		4,335	2,923
Total past due		7,792	6,246
Acquired impaired	[1]	6,863	7,299
Current		518,880	604,109
Total loans		533,535	617,654
Acquired Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		3,311	2,929
Consumer Mortgage [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		1,630,713	1,581,458
Consumer Mortgage [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		168,035	188,296
Business Lending [Member]
Aged analysis of the company's loans [Abstract]
Total loans		1,506,878	1,497,271
Business Lending [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		1,274,251	1,233,628
Business Lending [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		232,627	263,643
Consumer Indirect [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		1,003,842	890,339
Consumer Indirect [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		33,235	45,421
Consumer Direct [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		184,980	178,051
Consumer Direct [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		11,154	17,025
Home Equity [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		313,300	300,245
Home Equity [Member] | Acquired Loans [Member]
Aged analysis of the company's loans [Abstract]
Total loans		88,484	103,269
Residential Portfolio Segment [Member] | Consumer Mortgage [Member]
Aged analysis of the company's loans [Abstract]
Total loans		1,798,748	1,769,754
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		927	1,411
Nonaccrual		11,663	11,394
Total past due		22,262	23,287
Current		1,608,451	1,558,171
Total loans		1,630,713	1,581,458
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] | Legacy Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		9,672	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		61	394
Nonaccrual		2,464	1,396
Total past due		3,762	3,163
Acquired impaired	[1]	0	0
Current		164,273	185,133
Total loans		168,035	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		1,237	1,373
Commercial Portfolio Segment [Member] | Business Lending [Member]
Aged analysis of the company's loans [Abstract]
Total loans		1,506,878	1,497,271
Commercial Portfolio Segment [Member] | Business Lending [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		390	126
Nonaccrual		3,774	5,381
Total past due		7,159	9,949
Current		1,267,092	1,223,679
Total loans		1,274,251	1,233,628
Commercial Portfolio Segment [Member] | Business Lending [Member] | Legacy Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		2,995	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		1,460	1,186
Total past due		1,686	1,721
Acquired impaired	[1]	6,863	7,299
Current		224,078	254,623
Total loans		232,627	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		226	535
Consumer Portfolio Segment [Member] | Consumer Indirect [Member]
Aged analysis of the company's loans [Abstract]
Total loans		1,037,077	935,760
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		162	102
Nonaccrual		0	0
Total past due		10,819	11,677
Current		993,023	878,662
Total loans		1,003,842	890,339
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] | Legacy Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		10,657	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		15	0
Nonaccrual		0	0
Total past due		223	245
Acquired impaired	[1]	0	0
Current		33,012	45,176
Total loans		33,235	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		208	245
Consumer Portfolio Segment [Member] | Consumer Direct [Member]
Aged analysis of the company's loans [Abstract]
Total loans		196,134	195,076
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		86	51
Nonaccrual		0	1
Total past due		1,404	1,466
Current		183,576	176,585
Total loans		184,980	178,051
Consumer Portfolio Segment [Member] | Consumer Direct [Member] | Legacy Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		1,318	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		166	154
Acquired impaired	[1]	0	0
Current		10,988	16,871
Total loans		11,154	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		166	140
Consumer Portfolio Segment [Member] | Home Equity [Member]
Aged analysis of the company's loans [Abstract]
Total loans		401,784	403,514
Consumer Portfolio Segment [Member] | Home Equity [Member] | Legacy Loans [Member]
Aged analysis of the company's loans [Abstract]
90 + days past due and still accruing		304	111
Nonaccrual		1,529	2,029
Total past due		3,038	3,233
Current		310,262	297,012
Total loans		313,300	300,245
Consumer Portfolio Segment [Member] | Home Equity [Member] | Legacy Loans [Member] | Past Due 30 - 89 Days [Member]
Aged analysis of the company's loans [Abstract]
Total past due		1,205	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		70	0
Nonaccrual		411	327
Total past due		1,955	963
Acquired impaired	[1]	0	0
Current		86,529	102,306
Total loans		88,484	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		$ 1,474	$ 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.