Loans Receivable, Net (Details 1) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Dec. 31, 2010
Allowance for loan and lease losses
Individually evaluated for impairment	$ 18,562		$ 18,828
Collectively evaluated for impairment	118,098		118,688
Total allowances for loan and lease losses	136,660	137,459	137,516	138,093	139,795	137,107
Loans receivable
Individually evaluated for impairment	226,440		258,659
Collectively evaluated for impairment	3,181,654		3,207,476
Total loans receivable	3,408,094		3,466,135
Residential Real Estate [Member]
Allowance for loan and lease losses
Individually evaluated for impairment	3,252		2,659
Collectively evaluated for impairment	13,997		14,568
Total allowances for loan and lease losses	17,249	18,139	17,227	19,263	17,412	20,957
Loans receivable
Individually evaluated for impairment	29,945		24,453
Collectively evaluated for impairment	498,232		492,354
Total loans receivable	528,177		516,807
Commercial Real Estate [Member]
Allowance for loan and lease losses
Individually evaluated for impairment	8,410		9,756
Collectively evaluated for impairment	69,345		67,164
Total allowances for loan and lease losses	77,755	79,098	76,920	75,690	79,885	76,147
Loans receivable
Individually evaluated for impairment	141,717		162,959
Collectively evaluated for impairment	1,510,335		1,509,100
Total loans receivable	1,652,052		1,672,059
Other Commercial [Member]
Allowance for loan and lease losses
Individually evaluated for impairment	4,436		4,233
Collectively evaluated for impairment	17,793		16,600
Total allowances for loan and lease losses	22,229	20,570	20,833	20,623	19,615	19,932
Loans receivable
Individually evaluated for impairment	35,672		49,962
Collectively evaluated for impairment	585,235		573,906
Total loans receivable	620,907		623,868
Home Equity [Member]
Allowance for loan and lease losses
Individually evaluated for impairment	257		584
Collectively evaluated for impairment	9,727		13,032
Total allowances for loan and lease losses	9,984	10,904	13,616	13,846	13,625	13,334
Loans receivable
Individually evaluated for impairment	12,054		14,750
Collectively evaluated for impairment	394,850		425,819
Total loans receivable	406,904		440,569
Other Consumer [Member]
Allowance for loan and lease losses
Individually evaluated for impairment	2,207		1,596
Collectively evaluated for impairment	7,236		7,324
Total allowances for loan and lease losses	9,443	8,748	8,920	8,671	9,258	6,737
Loans receivable
Individually evaluated for impairment	7,052		6,535
Collectively evaluated for impairment	193,002		206,297
Total loans receivable	$ 200,054		$ 212,832