Allowance for Loan and Lease Losses (Details 2) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 3,056,310	$ 2,955,473
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	694,336	692,080
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1,361,849	1,303,867
Residential real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	906,620	856,856
Consumer and other, total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	56,909	60,452
Finance Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	5,048	4,618
Covered Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	31,548	37,600
Orginated Loans and Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually Evaluated For Impairment	22,804	24,732
Collectively Evaluated For Impairment	2,287,555	2,109,237
Total	2,310,359	2,133,969
Orginated Loans and Leases | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually Evaluated For Impairment	4,615	2,771
Collectively Evaluated For Impairment	552,298	521,882
Total	556,913	524,653
Orginated Loans and Leases | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually Evaluated For Impairment	17,742	21,478
Collectively Evaluated For Impairment	880,946	790,709
Total	898,688	812,187
Orginated Loans and Leases | Residential real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually Evaluated For Impairment	447	483
Collectively Evaluated For Impairment	793,740	733,098
Total	794,187	733,581
Orginated Loans and Leases | Consumer and other, total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually Evaluated For Impairment	0	0
Collectively Evaluated For Impairment	55,523	58,930
Total	55,523	58,930
Orginated Loans and Leases | Finance Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually Evaluated For Impairment	0	0
Collectively Evaluated For Impairment	5,048	4,618
Total	5,048	4,618
Orginated Loans and Leases | Covered Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Acquired Loans and Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually Evaluated For Impairment	3,722	0
Loans Acquired With Deteriorated Credit Quality	66,594	85,077
Collectively Evaluated For Impairment	675,635	736,427
Total	745,951	821,504
Acquired Loans and Leases | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually Evaluated For Impairment	1,045	519
Loans Acquired With Deteriorated Credit Quality	4,386	7,144
Collectively Evaluated For Impairment	131,992	159,764
Total	137,423	167,427
Acquired Loans and Leases | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually Evaluated For Impairment	2,677	1,816
Loans Acquired With Deteriorated Credit Quality	16,530	24,032
Collectively Evaluated For Impairment	443,953	465,832
Total	463,161	491,680
Acquired Loans and Leases | Residential real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually Evaluated For Impairment	0	0
Loans Acquired With Deteriorated Credit Quality	14,130	17,650
Collectively Evaluated For Impairment	98,303	105,625
Total	112,433	123,275
Acquired Loans and Leases | Consumer and other, total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually Evaluated For Impairment	0	0
Loans Acquired With Deteriorated Credit Quality	0	0
Collectively Evaluated For Impairment	1,386	1,522
Total	1,386	1,522
Acquired Loans and Leases | Finance Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Acquired Loans and Leases | Covered Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually Evaluated For Impairment	0	0
Loans Acquired With Deteriorated Credit Quality	31,548	36,251
Collectively Evaluated For Impairment	1	1,349
Total	$ 31,548	$ 37,600