Allowance for Loan and Lease Losses (Details 2) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 3,823,818	$ 3,774,832
Commercial and industrial, total [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	930,479	941,133
Commercial real estate, total [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1,706,219	1,649,161
Residential real estate, total [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1,101,256	1,096,002
Consumer and other, total [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	58,701	59,644
Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	14,426	14,861
Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	12,737	14,031
Originated Loans and Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	9,226	9,131
Collectively Evaluated For Impairment	3,364,470	3,304,427
Total	3,373,696	3,313,558
Originated Loans and Leases [Member] | Commercial and industrial, total [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	629	1,206
Collectively Evaluated For Impairment	843,308	855,117
Total	843,937	856,323
Originated Loans and Leases [Member] | Commercial real estate, total [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	6,286	5,655
Collectively Evaluated For Impairment	1,417,788	1,351,567
Total	1,424,074	1,357,222
Originated Loans and Leases [Member] | Residential real estate, total [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	2,311	2,270
Collectively Evaluated For Impairment	1,031,232	1,024,149
Total	1,033,543	1,026,419
Originated Loans and Leases [Member] | Consumer and other, total [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	0	0
Collectively Evaluated For Impairment	57,716	58,733
Total	57,716	58,733
Originated Loans and Leases [Member] | Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	0	0
Collectively Evaluated For Impairment	14,426	14,861
Total	14,426	14,861
Originated Loans and Leases [Member] | Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Acquired Loans and Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	6,897	7,050
Loans acquired with deteriorated credit quality	25,460	26,507
Collectively Evaluated For Impairment	417,765	427,717
Total	450,122	461,274
Acquired Loans and Leases [Member] | Commercial and industrial, total [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	566	647
Loans acquired with deteriorated credit quality	515	567
Collectively Evaluated For Impairment	85,461	83,596
Total	86,542	84,810
Acquired Loans and Leases [Member] | Commercial real estate, total [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	5,078	5,226
Loans acquired with deteriorated credit quality	9,086	9,335
Collectively Evaluated For Impairment	267,981	277,378
Total	282,145	291,939
Acquired Loans and Leases [Member] | Residential real estate, total [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	1,253	1,177
Loans acquired with deteriorated credit quality	3,762	3,801
Collectively Evaluated For Impairment	62,698	64,605
Total	67,713	69,583
Acquired Loans and Leases [Member] | Consumer and other, total [Member]
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	985	911
Total	985	911
Acquired Loans and Leases [Member] | Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Acquired Loans and Leases [Member] | Covered Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	0	0
Loans acquired with deteriorated credit quality	12,097	12,804
Collectively Evaluated For Impairment	640	1,227
Total	$ 12,737	$ 14,031