LOANS, ALLOWANCE FOR LOAN LOSSES AND CREDIT QUALITY (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended										12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012		Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance					$ 51,834					$ 48,260	$ 51,834		$ 48,260		$ 46,255
Charge-offs											(10,518)		(16,592)		(11,341)
Recoveries											1,723		2,110		1,864
Provision	3,150		2,650	3,100	1,300	4,350		3,606	8,500	1,600	10,200		18,056		11,482
Ending balance	53,239					51,834					53,239		51,834		48,260
Ending balance: individually evaluated for impairment	3,774					3,420					3,774		3,420		2,682
Ending balance: collectively evaluated for impairment	49,465					48,414					49,465		48,414		45,578
Financing receivables
Total loans	4,718,307	[1]				4,519,011	[1]				4,718,307	[1]	4,519,011	[1]	3,794,390	[1]
Ending balance: individually evaluated for impairment	72,055					66,659					72,055		66,659		61,701
Financing Receivable, Acquired with Deteriorated Credit Quality	29,544					32,054					29,544		32,054
Ending balance: collectively evaluated for impairment	4,616,708					4,420,298					4,616,708		4,420,298		3,732,689
Commercial and Industrial [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance					13,461					11,682	13,461		11,682		10,423
Charge-offs											(2,683)		(6,191)		(2,888)
Recoveries											272		963		420
Provision											4,572		7,007		3,727
Ending balance	15,622					13,461					15,622		13,461		11,682
Ending balance: individually evaluated for impairment	1,150					1,084					1,150		1,084		562
Ending balance: collectively evaluated for impairment	14,472					12,377					14,472		12,377		11,120
Financing receivables
Total loans	784,202					687,511					784,202		687,511		575,716
Ending balance: individually evaluated for impairment	9,148					8,575					9,148		8,575		5,608
Financing Receivable, Acquired with Deteriorated Credit Quality	1					0					1		0
Ending balance: collectively evaluated for impairment	775,053					678,936					775,053		678,936		570,108
Commercial Real Estate [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance					22,598					23,514	22,598		23,514		21,939
Charge-offs											(3,587)		(4,348)		(2,631)
Recoveries											206		188		97
Provision											5,324		3,244		4,109
Ending balance	24,541					22,598					24,541		22,598		23,514
Ending balance: individually evaluated for impairment	765					516					765		516		457
Ending balance: collectively evaluated for impairment	23,776					22,082					23,776		22,082		23,057
Financing receivables
Total loans	2,249,260					2,122,153					2,249,260		2,122,153		1,847,654
Ending balance: individually evaluated for impairment	39,516					33,868					39,516		33,868		37,476
Financing Receivable, Acquired with Deteriorated Credit Quality	18,612					21,853					18,612		21,853
Ending balance: collectively evaluated for impairment	2,191,132					2,066,432					2,191,132		2,066,432		1,810,178
Commercial Construction [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance					2,811					2,076	2,811		2,076		2,145
Charge-offs											(308)				(769)
Recoveries											100				500
Provision											768		735		200
Ending balance	3,371					2,811					3,371		2,811		2,076
Ending balance: individually evaluated for impairment
Ending balance: collectively evaluated for impairment	3,371					2,811					3,371		2,811		2,076
Financing receivables
Total loans	223,859					188,768					223,859		188,768		128,904
Ending balance: individually evaluated for impairment	100										100				843
Financing Receivable, Acquired with Deteriorated Credit Quality	197					0					197		0
Ending balance: collectively evaluated for impairment	223,562					188,768					223,562		188,768		128,061
Small Business [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance					1,524					1,896	1,524		1,896		3,740
Charge-offs											(773)		(616)		(1,190)
Recoveries											279		134		160
Provision											185		110		(814)
Ending balance	1,215					1,524					1,215		1,524		1,896
Ending balance: individually evaluated for impairment	109					353					109		353		148
Ending balance: collectively evaluated for impairment	1,106					1,171					1,106		1,171		1,748
Financing receivables
Total loans	77,240					78,594					77,240		78,594		78,509
Ending balance: individually evaluated for impairment	1,903					2,279					1,903		2,279		2,326
Financing Receivable, Acquired with Deteriorated Credit Quality	0					0					0		0
Ending balance: collectively evaluated for impairment	75,337					76,315					75,337		76,315		76,183
Residential Real Estate [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance					2,930					3,113	2,930		3,113		2,915
Charge-offs											(622)		(1,094)		(559)
Recoveries											143		151
Provision											309		760		757
Ending balance	2,760					2,930					2,760		2,930		3,113
Ending balance: individually evaluated for impairment	1,564					1,302					1,564		1,302		1,245
Ending balance: collectively evaluated for impairment	1,196					1,628					1,196		1,628		1,868
Financing receivables
Total loans	541,443					612,881					541,443		612,881		426,201
Ending balance: individually evaluated for impairment	15,200					15,373					15,200		15,373		12,984
Financing Receivable, Acquired with Deteriorated Credit Quality	10,389					9,821					10,389		9,821
Ending balance: collectively evaluated for impairment	515,854					587,687					515,854		587,687		413,217
Home Equity [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance					7,703					4,597	7,703		4,597		3,369
Charge-offs											(1,370)		(3,178)		(1,626)
Recoveries											135		93		52
Provision											(1,432)		6,191		2,802
Ending balance	5,036					7,703					5,036		7,703		4,597
Ending balance: individually evaluated for impairment	116					35					116		35		31
Ending balance: collectively evaluated for impairment	4,920					7,668					4,920		7,668		4,566
Financing receivables
Total loans	822,141					802,149					822,141		802,149		696,063
Ending balance: individually evaluated for impairment	4,890					4,435					4,890		4,435		326
Financing Receivable, Acquired with Deteriorated Credit Quality	326					380					326		380
Ending balance: collectively evaluated for impairment	816,925					797,334					816,925		797,334		695,737
Consumer Other [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance					807					1,382	807		1,382		1,724
Charge-offs											(1,175)		(1,165)		(1,678)
Recoveries											588		581		635
Provision											474		9		701
Ending balance	694					807					694		807		1,382
Ending balance: individually evaluated for impairment	70					130					70		130		239
Ending balance: collectively evaluated for impairment	624					677					624		677		1,143
Financing receivables
Total loans	20,162					26,955					20,162		26,955		41,343
Ending balance: individually evaluated for impairment	1,298					2,129					1,298		2,129		2,138
Financing Receivable, Acquired with Deteriorated Credit Quality	19					0					19		0
Ending balance: collectively evaluated for impairment	$ 18,845					$ 24,826					$ 18,845		$ 24,826		$ 39,205

[1] The amount of deferred fees included in the ending balance was $2.3 million, $3.1 million, and $2.9 million at December 31, 2013, 2012, and 2011, respectively.