LOANS (Details) (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011	Dec. 31, 2012 Consumer Mortgage [Member]		Dec. 31, 2011 Consumer Mortgage [Member]	Dec. 31, 2012 Business Lending [Member]		Dec. 31, 2011 Business Lending [Member]	Dec. 31, 2012 Home Equity Receivables [Member]		Dec. 31, 2011 Home Equity Receivables [Member]	Dec. 31, 2012 Consumer Installment Direct [Member]		Dec. 31, 2011 Consumer Installment Direct [Member]	Dec. 31, 2012 Consumer Installment Indirect [Member]		Dec. 31, 2011 Consumer Installment Indirect [Member]	Dec. 31, 2012 Unallocated [Member]	Dec. 31, 2011 Unallocated [Member]	Dec. 31, 2012 Acquired Impaired [Member]	Dec. 31, 2011 Acquired Impaired [Member]	Dec. 31, 2012 Acquired Loans [Member]		Dec. 31, 2011 Acquired Loans [Member]		Dec. 31, 2012 Legacy Loan [Member]	Dec. 31, 2011 Legacy Loan [Member]	Dec. 31, 2012 Pass [Member]	Dec. 31, 2011 Pass [Member]	Dec. 31, 2012 Pass [Member] Acquired Loans [Member]	Dec. 31, 2011 Pass [Member] Acquired Loans [Member]	Dec. 31, 2012 Pass [Member] Legacy Loan [Member]	Dec. 31, 2011 Pass [Member] Legacy Loan [Member]	Dec. 31, 2012 Special Mention [Member]	Dec. 31, 2011 Special Mention [Member]	Dec. 31, 2012 Special Mention [Member] Acquired Loans [Member]	Dec. 31, 2011 Special Mention [Member] Acquired Loans [Member]	Dec. 31, 2012 Special Mention [Member] Legacy Loan [Member]	Dec. 31, 2011 Special Mention [Member] Legacy Loan [Member]	Dec. 31, 2012 Classified [Member]	Dec. 31, 2011 Classified [Member]	Dec. 31, 2012 Classified [Member] Acquired Loans [Member]	Dec. 31, 2011 Classified [Member] Acquired Loans [Member]	Dec. 31, 2012 Classified [Member] Legacy Loan [Member]	Dec. 31, 2011 Classified [Member] Legacy Loan [Member]	Dec. 31, 2012 Doubtful [Member]	Dec. 31, 2011 Doubtful [Member]	Dec. 31, 2012 Doubtful [Member] Acquired Loans [Member]	Dec. 31, 2011 Doubtful [Member] Acquired Loans [Member]	Dec. 31, 2012 Doubtful [Member] Legacy Loan [Member]	Dec. 31, 2011 Doubtful [Member] Legacy Loan [Member]	Dec. 31, 2012 Acquired Impaired Loans [Member]	Dec. 31, 2011 Acquired Impaired Loans [Member]	Dec. 31, 2012 Acquired Impaired Loans [Member] Acquired Loans [Member]	Dec. 31, 2011 Acquired Impaired Loans [Member] Acquired Loans [Member]	Dec. 31, 2012 Acquired Impaired Loans [Member] Legacy Loan [Member]	Dec. 31, 2011 Acquired Impaired Loans [Member] Legacy Loan [Member]	Dec. 31, 2012 Performing [Member] Acquired Loans [Member]	Dec. 31, 2011 Performing [Member] Acquired Loans [Member]	Dec. 31, 2012 Performing [Member] Legacy Loan [Member]	Dec. 31, 2011 Performing [Member] Legacy Loan [Member]	Dec. 31, 2012 Nonperforming [Member] Acquired Loans [Member]	Dec. 31, 2011 Nonperforming [Member] Acquired Loans [Member]	Dec. 31, 2012 Nonperforming [Member] Legacy Loan [Member]	Dec. 31, 2011 Nonperforming [Member] Legacy Loan [Member]	Dec. 31, 2012 Consumer Mortgage [Member] Acquired Loans [Member]		Dec. 31, 2011 Consumer Mortgage [Member] Acquired Loans [Member]		Dec. 31, 2012 Consumer Mortgage [Member] Legacy Loan [Member]	Dec. 31, 2011 Consumer Mortgage [Member] Legacy Loan [Member]	Dec. 31, 2012 Consumer Mortgage [Member] Performing [Member] Acquired Loans [Member]	Dec. 31, 2011 Consumer Mortgage [Member] Performing [Member] Acquired Loans [Member]	Dec. 31, 2012 Consumer Mortgage [Member] Performing [Member] Legacy Loan [Member]	Dec. 31, 2011 Consumer Mortgage [Member] Performing [Member] Legacy Loan [Member]	Dec. 31, 2012 Consumer Mortgage [Member] Nonperforming [Member] Acquired Loans [Member]	Dec. 31, 2011 Consumer Mortgage [Member] Nonperforming [Member] Acquired Loans [Member]	Dec. 31, 2012 Consumer Mortgage [Member] Nonperforming [Member] Legacy Loan [Member]	Dec. 31, 2011 Consumer Mortgage [Member] Nonperforming [Member] Legacy Loan [Member]	Dec. 31, 2012 Business Lending [Member] Acquired Loans [Member]		Dec. 31, 2011 Business Lending [Member] Acquired Loans [Member]		Dec. 31, 2012 Business Lending [Member] Legacy Loan [Member]	Dec. 31, 2011 Business Lending [Member] Legacy Loan [Member]	Dec. 31, 2012 Consumer Indirect [Member] Acquired Loans [Member]		Dec. 31, 2011 Consumer Indirect [Member] Acquired Loans [Member]		Dec. 31, 2012 Consumer Indirect [Member] Legacy Loan [Member]	Dec. 31, 2011 Consumer Indirect [Member] Legacy Loan [Member]	Dec. 31, 2012 Consumer Indirect [Member] Performing [Member] Acquired Loans [Member]	Dec. 31, 2011 Consumer Indirect [Member] Performing [Member] Acquired Loans [Member]	Dec. 31, 2012 Consumer Indirect [Member] Performing [Member] Legacy Loan [Member]	Dec. 31, 2011 Consumer Indirect [Member] Performing [Member] Legacy Loan [Member]	Dec. 31, 2012 Consumer Indirect [Member] Nonperforming [Member] Acquired Loans [Member]	Dec. 31, 2011 Consumer Indirect [Member] Nonperforming [Member] Acquired Loans [Member]	Dec. 31, 2012 Consumer Indirect [Member] Nonperforming [Member] Legacy Loan [Member]	Dec. 31, 2011 Consumer Indirect [Member] Nonperforming [Member] Legacy Loan [Member]	Dec. 31, 2012 Consumer Direct [Member] Acquired Loans [Member]		Dec. 31, 2011 Consumer Direct [Member] Acquired Loans [Member]		Dec. 31, 2012 Consumer Direct [Member] Legacy Loan [Member]	Dec. 31, 2011 Consumer Direct [Member] Legacy Loan [Member]	Dec. 31, 2012 Consumer Direct [Member] Performing [Member] Acquired Loans [Member]	Dec. 31, 2011 Consumer Direct [Member] Performing [Member] Acquired Loans [Member]	Dec. 31, 2012 Consumer Direct [Member] Performing [Member] Legacy Loan [Member]	Dec. 31, 2011 Consumer Direct [Member] Performing [Member] Legacy Loan [Member]	Dec. 31, 2012 Consumer Direct [Member] Nonperforming [Member] Acquired Loans [Member]	Dec. 31, 2011 Consumer Direct [Member] Nonperforming [Member] Acquired Loans [Member]	Dec. 31, 2012 Consumer Direct [Member] Nonperforming [Member] Legacy Loan [Member]	Dec. 31, 2011 Consumer Direct [Member] Nonperforming [Member] Legacy Loan [Member]	Dec. 31, 2012 Home Equity Receivables [Member] Acquired Loans [Member]		Dec. 31, 2011 Home Equity Receivables [Member] Acquired Loans [Member]		Dec. 31, 2012 Home Equity Receivables [Member] Legacy Loan [Member]	Dec. 31, 2011 Home Equity Receivables [Member] Legacy Loan [Member]	Dec. 31, 2012 Home Equity Receivables [Member] Performing [Member] Acquired Loans [Member]	Dec. 31, 2011 Home Equity Receivables [Member] Performing [Member] Acquired Loans [Member]	Dec. 31, 2012 Home Equity Receivables [Member] Performing [Member] Legacy Loan [Member]	Dec. 31, 2011 Home Equity Receivables [Member] Performing [Member] Legacy Loan [Member]	Dec. 31, 2012 Home Equity Receivables [Member] Nonperforming [Member] Acquired Loans [Member]	Dec. 31, 2011 Home Equity Receivables [Member] Nonperforming [Member] Acquired Loans [Member]	Dec. 31, 2012 Home Equity Receivables [Member] Nonperforming [Member] Legacy Loan [Member]	Dec. 31, 2011 Home Equity Receivables [Member] Nonperforming [Member] Legacy Loan [Member]	Apr. 08, 2011 Wilber Corporation [Member]	Jul. 20, 2012 HSBC Branch Agreement [Member]	Sep. 07, 2012 First Niagara Branch Agreement [Member]	Dec. 31, 2012 Consumer Mortgage [Member]	Dec. 31, 2011 Consumer Mortgage [Member]	Dec. 31, 2012 Business Lending [Member]	Dec. 31, 2011 Business Lending [Member]	Dec. 31, 2012 Consumer Indirect [Member]	Dec. 31, 2011 Consumer Indirect [Member]	Dec. 31, 2012 Consumer Direct [Member]	Dec. 31, 2011 Consumer Direct [Member]	Dec. 31, 2012 Home Equity Receivables [Member]	Dec. 31, 2011 Home Equity Receivables [Member]
Loans receivable, net [Abstract]
Gross loans, including net deferred origination costs	$ 3,865,576,000		$ 3,471,025,000																				$ 447,355,000		$ 395,546,000		$ 3,418,221,000	$ 3,075,479,000																																							$ 103,128,000		$ 78,901,000		$ 1,345,287,000	$ 1,135,720,000									$ 231,090,000		$ 256,540,000		$ 1,002,854,000	$ 969,899,000	$ 10,161,000		$ 21,046,000		$ 637,357,000	$ 535,909,000									$ 15,208,000		$ 8,663,000		$ 156,266,000	$ 140,507,000									$ 87,768,000		$ 30,396,000		$ 276,457,000	$ 293,444,000												$ 1,448,415,000	$ 1,214,621,000	$ 1,233,944,000	$ 1,226,439,000	$ 647,518,000	$ 556,955,000	$ 171,474,000	$ 149,170,000	$ 364,225,000	$ 323,840,000
Allowance for loan losses	(42,888,000)		(42,213,000)	(7,070,000)		(4,651,000)	(18,013,000)		(20,574,000)	(1,451,000)		(1,130,000)	(3,303,000)		(3,290,000)	(9,606,000)		(8,960,000)	(2,666,000)	(3,222,000)	(779,000)	(386,000)
Loans, net of allowance for loan losses	3,822,688,000		3,428,812,000
Net deferred loan origination costs	16,500,000		13,700,000
Loans receivable, related parties [Roll Forward]
Balance at beginning of period	11,550,000		18,765,000
New loans	2,259,000		2,690,000
Payments	(5,517,000)		(9,905,000)
Balance at end of period	8,292,000		11,550,000
Business Acquisition [Line Items]
Loans acquired																																																																																																																																	462,000,000	106,000,000	54,000,000
Credit impaired acquired loans: [Abstract]
Outstanding principal balance	19,940,000		24,819,000
Carrying amount	13,761,000		17,428,000
Non-impaired acquired loans: [Abstract]
Outstanding principal balance	449,739,000		396,014,000
Carrying amount	433,594,000		378,118,000
Total acquired loans: [Abstract]
Outstanding principal balance	469,679,000		420,833,000
Carrying amount	447,355,000		395,546,000
Aged analysis of the company's loans [Abstract]
30 - 89 days																							7,254,000		5,827,000		37,938,000	33,853,000																																							1,726,000		985,000		16,334,000	16,026,000									3,665,000		3,473,000		6,012,000	4,799,000	434,000		737,000		9,743,000	8,847,000									470,000		167,000		1,725,000	1,912,000									959,000		465,000		4,124,000	2,269,000
90 plus Days Past Due and Still Accruing																							393,000		212,000		2,355,000	2,878,000																																							265,000		27,000		1,553,000	2,144,000									80,000		10,000		167,000	389,000	0		0		73,000	32,000									0		0		71,000	95,000									48,000		175,000		491,000	218,000
Nonaccrual																							4,432,000		10,700,000		21,928,000	17,585,000																																							2,420,000		765,000		8,866,000	5,755,000									1,681,000		9,592,000		12,010,000	10,966,000	0		2,000		0	0									0		0		8,000	0									331,000		341,000		1,044,000	864,000
Total Past Due																							12,079,000		16,739,000		62,221,000	54,316,000																																							4,411,000		1,777,000		26,753,000	23,925,000									5,426,000		13,075,000		18,189,000	16,154,000	434,000		739,000		9,816,000	8,879,000									470,000		167,000		1,804,000	2,007,000									1,338,000		981,000		5,659,000	3,351,000
Purchased Impaired																							13,761,000	[1]	17,428,000	[1]																																									0	[1]	0	[1]											13,761,000	[1]	17,428,000	[1]			0	[1]	0	[1]											0	[1]	0	[1]											0	[1]	0	[1]
Current																							421,155,000		361,379,000		3,356,000,000	3,021,163,000																																							98,717,000		77,124,000		1,318,534,000	1,111,795,000									211,903,000		226,037,000		984,665,000	953,745,000	9,727,000		20,307,000		627,541,000	527,030,000									14,378,000		8,496,000		154,462,000	138,500,000									86,430,000		29,415,000		270,798,000	290,093,000
Gross loans, including deferred origination costs	3,865,576,000		3,471,025,000																				447,355,000		395,546,000		3,418,221,000	3,075,479,000																																							103,128,000		78,901,000		1,345,287,000	1,135,720,000									231,090,000		256,540,000		1,002,854,000	969,899,000	10,161,000		21,046,000		637,357,000	535,909,000									15,208,000		8,663,000		156,266,000	140,507,000									87,768,000		30,396,000		276,457,000	293,444,000												1,448,415,000	1,214,621,000	1,233,944,000	1,226,439,000	647,518,000	556,955,000	171,474,000	149,170,000	364,225,000	323,840,000
Business lending	1,233,944,000		1,226,439,000																				231,090,000		256,540,000		1,002,854,000	969,899,000	963,338,000	890,367,000	144,869,000	157,494,000	818,469,000	732,873,000	125,067,000	166,690,000	32,328,000	47,890,000	92,739,000	118,800,000	130,167,000	151,954,000	40,132,000	33,728,000	90,035,000	118,226,000	1,611,000	0	0	0	1,611,000	0	13,761,000	17,428,000	13,761,000	17,428,000	0	0
Loans except business lending																							216,265,000		139,006,000		2,415,367,000	2,105,580,000																															213,201,000	137,696,000	2,403,261,000	2,096,472,000	3,064,000	1,310,000	12,106,000	9,108,000	103,128,000		78,901,000		1,345,287,000	1,135,720,000	100,443,000	78,109,000	1,334,868,000	1,127,821,000	2,685,000	792,000	10,419,000	7,899,000							10,161,000		21,046,000		637,357,000	535,909,000	10,161,000	21,044,000	637,284,000	535,877,000	0	2,000	73,000	32,000	15,208,000		8,663,000		156,266,000	140,507,000	15,208,000	8,663,000	156,187,000	140,412,000	0	0	79,000	95,000	87,768,000		30,396,000		276,457,000	293,444,000	87,389,000	29,880,000	274,922,000	292,362,000	379,000	516,000	1,535,000	1,082,000
Impaired loans [Abstract]
Loans with reserve	1,611,000		4,118,000
Loans without specific reserve	7,798,000		2,308,000
Carrying balance	9,409,000		6,426,000
Contractual balance	12,804,000		8,527,000
Specifically allocated allowance	800,000		895,000
Average impaired loans	19,787,000		5,652,000
Interest income recognized	185,000		314,000
Allowance for loan losses [Roll Forward]
TDR individual evaluated for impairment	500,000
TDR impaired loan balance	2,000,000
Specific reserve related to TDR impaired loan balance	800,000
General loan loss allocation and the qualitative review, minimum	500,000
Troubled debt restructurings , nonaccrual, number of loans	18			3			10			5			0			0
Troubled debt restructurings , Nonaccrual amount	3,276,000			160,000			3,046,000			70,000			0			0
Troubled debt restructurings , Accruing	189	[2]		45	[2]		0	[2]		19	[2]		19	[2]		106	[2]
Troubled debt restructurings , Accruing amount	3,174,000	[2]		2,074,000	[2]		0	[2]		266,000	[2]		116,000	[2]		718,000	[2]
Troubled debt restructurings	207			48			10			24			19			106
Troubled debt restructurings , Total	6,450,000			2,234,000			3,046,000			336,000			116,000			718,000
TDR occurring during the year, number of contracts	104			23			9			12			13			47
TDR occurring during the year, post-modification recorded investment	4,387,000			1,176,000			2,709,000			126,000			95,000			281,000
Balance at beginning of period	42,213,000		42,510,000	4,651,000		2,451,000	20,574,000		22,326,000	1,130,000		689,000	3,290,000		3,977,000	8,960,000		9,922,000	3,222,000	3,145,000	386,000	0
Charge-offs	(14,182,000)		(9,714,000)	(1,004,000)		(748,000)	(5,654,000)		(2,964,000)	(423,000)		(265,000)	(1,694,000)		(1,273,000)	(5,407,000)		(4,464,000)	0	0	0	0
Recoveries	5,749,000		4,681,000	59,000		30,000	1,295,000		692,000	23,000		85,000	821,000		674,000	3,551,000		3,200,000	0	0	0	0
Provision	9,108,000		4,736,000	3,364,000		2,918,000	1,798,000		520,000	721,000		621,000	886,000		(88,000)	2,502,000		302,000	(556,000)	77,000	393,000	386,000
Balance at end of period	42,888,000		42,213,000	7,070,000		4,651,000	18,013,000		20,574,000	1,451,000		1,130,000	3,303,000		3,290,000	9,606,000		8,960,000	2,666,000	3,222,000	779,000	386,000
Accretable discount related to acquired loans [Roll forward]
Balance at beginning of year	2,610,000		0
Acquisition	0		2,509,000
Accretion recognized, to-date	(1,418,000)		(844,000)
Net reclassification to accretable from nonaccretable	578,000		945,000
Balance at end of year	$ 1,770,000		$ 2,610,000

[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 acquired impaired loans.

[2] Accruing loans have demonstrated a period of at least six months of payment performance under the restructured terms and are excluded from nonperforming loans