LOAN LOSS ALLOWANCE (Details 2) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Credit quality information
Loans	4,680,600,000	$ 4,180,523,000
Business Activity
Credit quality information
Loans	3,918,880,000	3,169,191,000
Acquired Loans
Credit quality information
Number of grades in internal loan rating system	11
Allowance for losses on acquired loans under Subtopic ASC 310-30		0
Loans	761,720,000	1,011,332,000
Residential | Mortgages
Credit quality information
Loans	1,496,204,000	1,384,274,000
Residential | Mortgages | Business Activity
Credit quality information
Loans	1,226,452,000	1,045,895,000
Residential | Mortgages | Acquired Loans
Credit quality information
Loans	269,752,000	338,379,000
Residential | Mortgages | 1-4 family
Credit quality information
Loans	1,468,142,000	1,361,104,000
Residential | Mortgages | 1-4 family | Business Activity
Credit quality information
Loans	1,199,408,000	1,027,737,000
Residential | Mortgages | 1-4 family | Acquired Loans
Credit quality information
Loans	268,734,000	333,367,000
Residential | Mortgages | Construction
Credit quality information
Loans	28,062,000	23,170,000
Residential | Mortgages | Construction | Business Activity
Credit quality information
Loans	27,044,000	18,158,000
Residential | Mortgages | Construction | Acquired Loans
Credit quality information
Loans	1,018,000	5,012,000
Commercial real estate
Credit quality information
Loans	1,611,567,000	1,417,120,000
Commercial real estate | Business Activity
Credit quality information
Loans	1,340,076,000	1,060,011,000
Commercial real estate | Acquired Loans
Credit quality information
Loans	271,491,000	357,109,000
Commercial real estate | Construction
Credit quality information
Loans	173,390,000	139,017,000
Commercial real estate | Construction | Business Activity
Credit quality information
Loans	169,189,000	125,247,000
Commercial real estate | Construction | Acquired Loans
Credit quality information
Loans	4,201,000	13,770,000
Commercial real estate | Single and multi-family
Credit quality information
Loans	193,218,000	128,320,000
Commercial real estate | Single and multi-family | Business Activity
Credit quality information
Loans	140,050,000	63,493,000
Commercial real estate | Single and multi-family | Acquired Loans
Credit quality information
Loans	53,168,000	64,827,000
Commercial real estate | Other commercial real estate
Credit quality information
Loans	1,244,959,000	1,149,783,000
Commercial real estate | Other commercial real estate | Business Activity
Credit quality information
Loans	1,030,837,000	871,271,000
Commercial real estate | Other commercial real estate | Acquired Loans
Credit quality information
Loans	214,122,000	278,512,000
Commercial real estate | Business loans
Credit quality information
Loans	804,366,000	687,293,000
Commercial real estate | Business loans | Business Activity
Credit quality information
Loans	753,191,000	617,437,000
Commercial real estate | Business loans | Acquired Loans
Credit quality information
Loans	51,175,000	69,856,000
Commercial real estate | Business loans | Asset based lending
Credit quality information
Loans	341,246,000	297,371,000
Commercial real estate | Business loans | Asset based lending | Business Activity
Credit quality information
Loans	341,246,000	294,241,000
Commercial real estate | Business loans | Asset based lending | Acquired Loans
Credit quality information
Loans		3,130,000
Commercial real estate | Business loans | Other commercial and industrial loans
Credit quality information
Loans	463,120,000	389,922,000
Commercial real estate | Business loans | Other commercial and industrial loans | Business Activity
Credit quality information
Loans	411,945,000	323,196,000
Commercial real estate | Business loans | Other commercial and industrial loans | Acquired Loans
Credit quality information
Loans	51,175,000	66,726,000
Commercial real estate | Business loans | Other commercial real estate | Other commercial and industrial loans | Business Activity
Credit quality information
Loans	411,945,000
Consumer
Credit quality information
Loans	768,463,000	691,836,000
Consumer | Business Activity
Credit quality information
Loans	599,161,000	445,848,000
Consumer | Acquired Loans
Credit quality information
Loans	169,302,000	245,988,000
Consumer | Home equity
Credit quality information
Loans	318,632,000	306,831,000
Consumer | Home equity | Business Activity
Credit quality information
Loans	252,681,000	232,677,000
Consumer | Home equity | Acquired Loans
Credit quality information
Loans	65,951,000	74,154,000
Consumer | Auto and other
Credit quality information
Loans	449,831,000	385,005,000
Consumer | Auto and other | Business Activity
Credit quality information
Loans	346,480,000	213,171,000
Consumer | Auto and other | Acquired Loans
Credit quality information
Loans	103,351,000	171,834,000
Consumer | Other
Credit quality information
Number of grades in internal loan rating system	2
Commercial
Credit quality information
Loans	2,415,933,000	2,104,413,000
Commercial | Business Activity
Credit quality information
Loans	2,093,267,000	1,677,448,000
Commercial | Acquired Loans
Credit quality information
Loans	322,666,000	426,965,000
Commercial | Mortgages | Acquired Loans
Credit quality information
Loans	271,491,000	357,109,000
Commercial | Mortgages | Construction | Acquired Loans
Credit quality information
Loans	4,201,000	13,770,000
Commercial | Mortgages | Single and multi-family | Acquired Loans
Credit quality information
Loans	53,168,000	64,827,000
Commercial | Mortgages | Other commercial real estate | Acquired Loans
Credit quality information
Loans	214,122,000	278,512,000
Commercial | Business loans | Business Activity
Credit quality information
Loans	753,191,000	617,437,000
Commercial | Business loans | Acquired Loans
Credit quality information
Loans	51,175,000	69,856,000
Commercial | Business loans | Asset based lending | Business Activity
Credit quality information
Loans	341,246,000	294,241,000
Commercial | Business loans | Asset based lending | Acquired Loans
Credit quality information
Loans		3,130,000
Commercial | Business loans | Other commercial and industrial loans | Business Activity
Credit quality information
Loans	411,945,000	323,196,000
Commercial | Business loans | Other commercial and industrial loans | Acquired Loans
Credit quality information
Loans	51,175,000	66,726,000
Pass | Residential | Mortgages | Maximum
Credit quality information
Period within which loans are current, based on which risk rating is assigned	59 days
Pass | Residential | Mortgages | Business Activity
Credit quality information
Loans	1,221,843,000	1,037,849,000
Pass | Residential | Mortgages | Acquired Loans
Credit quality information
Loans	267,463,000	331,434,000
Pass | Residential | Mortgages | 1-4 family | Business Activity
Credit quality information
Loans	1,195,209,000	1,019,732,000
Pass | Residential | Mortgages | 1-4 family | Acquired Loans
Credit quality information
Loans	266,445,000	330,353,000
Pass | Residential | Mortgages | Construction | Business Activity
Credit quality information
Loans	26,634,000	18,117,000
Pass | Residential | Mortgages | Construction | Acquired Loans
Credit quality information
Loans	1,018,000	1,081,000
Pass | Commercial real estate | Business Activity
Credit quality information
Loans	1,263,664,000	980,379,000
Pass | Commercial real estate | Construction | Business Activity
Credit quality information
Loans	166,295,000	120,071,000
Pass | Commercial real estate | Single and multi-family | Business Activity
Credit quality information
Loans	137,533,000	59,636,000
Pass | Commercial real estate | Other commercial real estate | Business Activity
Credit quality information
Loans	959,836,000	800,672,000
Pass | Commercial | Mortgages | Acquired Loans
Credit quality information
Loans	243,082,000	308,902,000
Pass | Commercial | Mortgages | Construction | Acquired Loans
Credit quality information
Loans	2,904,000	7,154,000
Pass | Commercial | Mortgages | Single and multi-family | Acquired Loans
Credit quality information
Loans	44,497,000	46,961,000
Pass | Commercial | Mortgages | Other commercial real estate | Acquired Loans
Credit quality information
Loans	195,681,000	254,787,000
Pass | Commercial | Business loans | Business Activity
Credit quality information
Loans	746,092,000	608,225,000
Pass | Commercial | Business loans | Acquired Loans
Credit quality information
Loans	45,757,000	62,745,000
Pass | Commercial | Business loans | Asset based lending | Business Activity
Credit quality information
Loans	341,246,000	294,241,000
Pass | Commercial | Business loans | Asset based lending | Acquired Loans
Credit quality information
Loans		3,130,000
Pass | Commercial | Business loans | Other commercial and industrial loans | Business Activity
Credit quality information
Loans	404,846,000	313,984,000
Pass | Commercial | Business loans | Other commercial and industrial loans | Acquired Loans
Credit quality information
Loans	45,757,000	59,615,000
Special mention
Credit quality information
Loans	17,913,000	27,934,000
Special mention | Business Activity
Credit quality information
Loans	9,113,000	10,081,000
Special mention | Acquired Loans
Credit quality information
Loans	8,800,000	17,853,000
Special mention | Residential | Mortgages | Minimum
Credit quality information
Delinquency period of loans based on which risk rating is assigned to loans	60 days
Special mention | Residential | Mortgages | Maximum
Credit quality information
Delinquency period of loans based on which risk rating is assigned to loans	89 days
Special mention | Residential | Mortgages | Business Activity
Credit quality information
Loans	556,000	623,000
Special mention | Residential | Mortgages | Acquired Loans
Credit quality information
Loans	638,000	437,000
Special mention | Residential | Mortgages | 1-4 family | Business Activity
Credit quality information
Loans	146,000	623,000
Special mention | Residential | Mortgages | 1-4 family | Acquired Loans
Credit quality information
Loans	638,000	437,000
Special mention | Residential | Mortgages | Construction | Business Activity
Credit quality information
Loans	410,000
Special mention | Commercial real estate | Business Activity
Credit quality information
Loans	6,933,000	8,290,000
Special mention | Commercial real estate | Single and multi-family | Business Activity
Credit quality information
Loans		140,000
Special mention | Commercial real estate | Other commercial real estate | Business Activity
Credit quality information
Loans	6,933,000	8,150,000
Special mention | Commercial | Mortgages | Acquired Loans
Credit quality information
Loans	5,401,000	13,833,000
Special mention | Commercial | Mortgages | Single and multi-family | Acquired Loans
Credit quality information
Loans	533,000	4,799,000
Special mention | Commercial | Mortgages | Other commercial real estate | Acquired Loans
Credit quality information
Loans	4,868,000	9,034,000
Special mention | Commercial | Business loans | Business Activity
Credit quality information
Loans	560,000	884,000
Special mention | Commercial | Business loans | Acquired Loans
Credit quality information
Loans	1,723,000	2,396,000
Special mention | Commercial | Business loans | Other commercial and industrial loans | Business Activity
Credit quality information
Loans	560,000	884,000
Special mention | Commercial | Business loans | Other commercial and industrial loans | Acquired Loans
Credit quality information
Loans	1,723,000	2,396,000
Substandard
Credit quality information
Loans	90,834,000	109,558,000
Substandard | Business Activity
Credit quality information
Loans	66,995,000	70,667,000
Substandard | Acquired Loans
Credit quality information
Loans	23,839,000	38,891,000
Substandard | Residential | Mortgages | Minimum
Credit quality information
Delinquency period of loans based on which risk rating is assigned to loans	90 days
Substandard | Residential | Mortgages | Business Activity
Credit quality information
Loans	4,053,000	7,423,000
Substandard | Residential | Mortgages | Acquired Loans
Credit quality information
Loans	1,651,000	6,508,000
Substandard | Residential | Mortgages | 1-4 family | Business Activity
Credit quality information
Loans	4,053,000	7,382,000
Substandard | Residential | Mortgages | 1-4 family | Acquired Loans
Credit quality information
Loans	1,651,000	2,577,000
Substandard | Residential | Mortgages | Construction | Business Activity
Credit quality information
Loans		41,000
Substandard | Residential | Mortgages | Construction | Acquired Loans
Credit quality information
Loans		3,931,000
Substandard | Commercial real estate | Business Activity
Credit quality information
Loans	69,406,000	70,700,000
Substandard | Commercial real estate | Construction | Business Activity
Credit quality information
Loans	2,894,000	5,176,000
Substandard | Commercial real estate | Single and multi-family | Business Activity
Credit quality information
Loans	2,517,000	3,717,000
Substandard | Commercial real estate | Other commercial real estate | Business Activity
Credit quality information
Loans	63,995,000	61,807,000
Substandard | Commercial | Mortgages | Acquired Loans
Credit quality information
Loans	23,008,000	34,374,000
Substandard | Commercial | Mortgages | Construction | Acquired Loans
Credit quality information
Loans	1,297,000	6,616,000
Substandard | Commercial | Mortgages | Single and multi-family | Acquired Loans
Credit quality information
Loans	8,138,000	13,067,000
Substandard | Commercial | Mortgages | Other commercial real estate | Acquired Loans
Credit quality information
Loans	13,573,000	14,691,000
Substandard | Commercial | Business loans | Business Activity
Credit quality information
Loans	6,539,000	7,725,000
Substandard | Commercial | Business loans | Acquired Loans
Credit quality information
Loans	3,695,000	4,715,000
Substandard | Commercial | Business loans | Other commercial and industrial loans | Business Activity
Credit quality information
Loans	6,539,000	7,725,000
Substandard | Commercial | Business loans | Other commercial and industrial loans | Acquired Loans
Credit quality information
Loans	3,695,000	4,715,000
Doubtful | Commercial real estate | Business Activity
Credit quality information
Loans	73,000	642,000
Doubtful | Commercial real estate | Other commercial real estate | Business Activity
Credit quality information
Loans	73,000	642,000
Doubtful | Commercial | Business loans | Business Activity
Credit quality information
Loans		603,000
Doubtful | Commercial | Business loans | Other commercial and industrial loans | Business Activity
Credit quality information
Loans		603,000
Performing | Consumer | Business Activity
Credit quality information
Loans	597,699,000	444,516,000
Performing | Consumer | Acquired Loans
Credit quality information
Loans	167,550,000	243,827,000
Performing | Consumer | Home equity | Business Activity
Credit quality information
Loans	251,524,000	231,594,000
Performing | Consumer | Home equity | Acquired Loans
Credit quality information
Loans	65,368,000	73,552,000
Performing | Consumer | Auto and other | Business Activity
Credit quality information
Loans	346,175,000	212,922,000
Performing | Consumer | Auto and other | Acquired Loans
Credit quality information
Loans	102,182,000	170,275,000
Performing | Consumer | Other | Maximum
Credit quality information
Period within which loans are current, based on which risk rating is assigned	119 days
Nonperforming | Consumer | Business Activity
Credit quality information
Loans	1,462,000	1,332,000
Nonperforming | Consumer | Acquired Loans
Credit quality information
Loans	1,752,000	2,161,000
Nonperforming | Consumer | Home equity | Business Activity
Credit quality information
Loans	1,157,000	1,083,000
Nonperforming | Consumer | Home equity | Acquired Loans
Credit quality information
Loans	583,000	602,000
Nonperforming | Consumer | Auto and other | Business Activity
Credit quality information
Loans	305,000	249,000
Nonperforming | Consumer | Auto and other | Acquired Loans
Credit quality information
Loans	1,169,000	1,559,000
Nonperforming | Consumer | Other | Minimum
Credit quality information
Delinquency period of loans based on which risk rating is assigned to loans	120 days
Non-Accrual
Credit quality information
Loans	21,705,000	27,455,000
Non-Accrual | Business Activity
Credit quality information
Loans	14,778,000	18,472,000
Non-Accrual | Acquired Loans
Credit quality information
Loans	6,927,000	8,983,000
Classified
Credit quality information
Loans	112,539,000	137,013,000
Classified | Business Activity
Credit quality information
Loans	81,773,000	89,139,000
Classified | Acquired Loans
Credit quality information
Loans	30,766,000	47,874,000
Criticized
Credit quality information
Loans	130,452,000	164,947,000
Criticized | Business Activity
Credit quality information
Loans	90,886,000	99,220,000
Criticized | Acquired Loans
Credit quality information
Loans	39,566,000	$ 65,727,000