LOANS (Details 3) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2012	Dec. 31, 2011
Activity in the allowance for loan losses
Balance at end of period	$ 33,090	$ 32,444
Allowance for loan losses
Total	33,090	32,444
Loans receivable: Balance at end of period
Total loans	3,418,392	2,956,570
Loans from Business Activities
Activity in the allowance for loan losses
Balance at beginning of period	31,898	31,898
Charged-off loans	6,210	7,696
Recoveries on charged-off loans	269	679
Provision for loan losses	6,017	7,017
Balance at end of period	31,974	31,898
Allowance for loan losses
Individually evaluated for impairment	2,765	2,775
Collectively evaluated	29,209	29,123
Total	31,974	31,898
Loans receivable: Balance at end of period
Individually evaluated for impairment	39,659	41,483
Collectively evaluated	2,592,424	2,220,768
Total loans	2,632,083	2,262,251
Loans Acquired from Business Combinations
Activity in the allowance for loan losses
Balance at beginning of period	546
Charged-off loans	167
Recoveries on charged-off loans	4
Provision for loan losses	733	546
Balance at end of period	1,116	546
Allowance for loan losses
Individually evaluated for impairment	44
Collectively evaluated	1,072	546
Total	1,116	546
Loans receivable: Balance at end of period
Individually evaluated for impairment	1,503
Collectively evaluated	784,806	694,319
Total loans	786,309	694,319
Residential mortgages
Loans receivable: Balance at end of period
Total loans	1,226,022	1,020,435
Residential mortgages | Loans from Business Activities
Activity in the allowance for loan losses
Balance at beginning of period	3,150	3,077
Charged-off loans	1,590	1,322
Recoveries on charged-off loans	87	231
Provision for loan losses	4,922	1,164
Balance at end of period	6,569	3,150
Allowance for loan losses
Individually evaluated for impairment	663	449
Collectively evaluated	5,906	2,701
Total	6,569	3,150
Loans receivable: Balance at end of period
Individually evaluated for impairment	6,534	5,655
Collectively evaluated	922,750	676,003
Total loans	929,284	681,658
Residential mortgages | Loans Acquired from Business Combinations
Activity in the allowance for loan losses
Balance at beginning of period	281
Charged-off loans	8
Provision for loan losses	165	281
Balance at end of period	438	281
Allowance for loan losses
Individually evaluated for impairment	44
Collectively evaluated	394	281
Total	438	281
Loans receivable: Balance at end of period
Individually evaluated for impairment	612
Collectively evaluated	296,126	338,777
Total loans	296,738	338,777
Commercial mortgages
Loans receivable: Balance at end of period
Total loans	1,255,172	1,156,241
Commercial mortgages | Loans from Business Activities
Activity in the allowance for loan losses
Balance at beginning of period	22,095	19,461
Charged-off loans	3,207	4,047
Recoveries on charged-off loans	8	189
Provision for loan losses	731	6,492
Balance at end of period	19,627	22,095
Allowance for loan losses
Individually evaluated for impairment	1,653	1,722
Collectively evaluated	17,974	20,373
Total	19,627	22,095
Loans receivable: Balance at end of period
Individually evaluated for impairment	30,819	34,074
Collectively evaluated	929,637	919,364
Total loans	960,456	953,438
Commercial mortgages | Loans Acquired from Business Combinations
Activity in the allowance for loan losses
Balance at beginning of period	158
Charged-off loans	85
Provision for loan losses	247	158
Balance at end of period	320	158
Allowance for loan losses
Collectively evaluated	320	158
Total	320	158
Loans receivable: Balance at end of period
Individually evaluated for impairment	891
Collectively evaluated	293,825	202,803
Total loans	294,716	202,803
Commercial business loans
Loans receivable: Balance at end of period
Total loans	568,781	410,292
Commercial business loans | Loans from Business Activities
Activity in the allowance for loan losses
Balance at beginning of period	4,540	6,038
Charged-off loans	116	1,443
Recoveries on charged-off loans	42	109
Provision for loan losses	267	(164)
Balance at end of period	4,733	4,540
Allowance for loan losses
Individually evaluated for impairment	342	116
Collectively evaluated	4,391	4,424
Total	4,733	4,540
Loans receivable: Balance at end of period
Individually evaluated for impairment	1,221	564
Collectively evaluated	474,291	361,202
Total loans	475,512	361,766
Commercial business loans | Loans Acquired from Business Combinations
Activity in the allowance for loan losses
Balance at beginning of period	38
Charged-off loans	34
Recoveries on charged-off loans	4
Provision for loan losses	82	38
Balance at end of period	90	38
Allowance for loan losses
Collectively evaluated	90	38
Total	90	38
Loans receivable: Balance at end of period
Collectively evaluated	93,269	48,526
Total loans	93,269	48,526
Consumer loans
Loans receivable: Balance at end of period
Total loans	368,417	369,602
Consumer loans | Loans from Business Activities
Activity in the allowance for loan losses
Balance at beginning of period	2,203	2,099
Charged-off loans	1,297	884
Recoveries on charged-off loans	132	150
Provision for loan losses	2	838
Balance at end of period	1,040	2,203
Allowance for loan losses
Individually evaluated for impairment	107	488
Collectively evaluated	933	1,715
Total	1,040	2,203
Loans receivable: Balance at end of period
Individually evaluated for impairment	1,085	1,190
Collectively evaluated	265,746	264,199
Total loans	266,831	265,389
Consumer loans | Loans Acquired from Business Combinations
Activity in the allowance for loan losses
Balance at beginning of period	87
Charged-off loans	40
Provision for loan losses	96	87
Balance at end of period	143	87
Allowance for loan losses
Collectively evaluated	143	87
Total	143	87
Loans receivable: Balance at end of period
Collectively evaluated	101,586	104,213
Total loans	101,586	104,213
Unallocated | Loans from Business Activities
Activity in the allowance for loan losses
Balance at beginning of period	(90)	1,223
Provision for loan losses	95	(1,313)
Balance at end of period	5	(90)
Allowance for loan losses
Collectively evaluated	5	(90)
Total	5	(90)
Unallocated | Loans Acquired from Business Combinations
Activity in the allowance for loan losses
Balance at beginning of period	(18)
Provision for loan losses	143	(18)
Balance at end of period	125	(18)
Allowance for loan losses
Collectively evaluated	125	(18)
Total	$ 125	$ (18)