Allowance for Loan and Lease Losses (Details 2) - USD ($)
$ in Thousands
Jun. 30, 2016
Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Total $ 3,981,336 $ 3,774,832
Commercial and industrial, total [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Total 976,289 941,133
Commercial real estate, total [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Total 1,778,612 1,649,161
Residential real estate, total [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Total 1,139,543 1,096,002
Consumer and other, total [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Total 59,936 59,644
Leases [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Total 14,687 14,861
Covered Loans [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Total 12,269 14,031
Originated Loans and Leases [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Individually evaluated for impairment 11,014 9,131
Collectively Evaluated For Impairment 3,543,837 3,304,427
Total 3,554,851 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 205 1,206
Collectively Evaluated For Impairment 891,137 855,117
Total 891,342 856,323
Originated Loans and Leases [Member] | Commercial real estate, total [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Individually evaluated for impairment 8,033 5,655
Collectively Evaluated For Impairment 1,506,823 1,351,567
Total 1,514,856 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 2,776 2,270
Collectively Evaluated For Impairment 1,072,231 1,024,149
Total 1,075,007 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 58,959 58,733
Total 58,959 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 14,687 14,861
Total 14,687 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 5,503 7,050
Loans acquired with deteriorated credit quality 24,587 26,507
Collectively Evaluated For Impairment 396,395 427,717
Total 426,485 461,274
Acquired Loans and Leases [Member] | Commercial and industrial, total [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Individually evaluated for impairment 59 647
Loans acquired with deteriorated credit quality 340 567
Collectively Evaluated For Impairment 84,548 83,596
Total 84,947 84,810
Acquired Loans and Leases [Member] | Commercial real estate, total [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Individually evaluated for impairment 4,177 5,226
Loans acquired with deteriorated credit quality 9,072 9,335
Collectively Evaluated For Impairment 250,507 277,378
Total 263,756 291,939
Acquired Loans and Leases [Member] | Residential real estate, total [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Individually evaluated for impairment 1,267 1,177
Loans acquired with deteriorated credit quality 3,532 3,801
Collectively Evaluated For Impairment 59,737 64,605
Total 64,536 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 977 911
Total 977 911
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 11,643 12,804
Collectively Evaluated For Impairment 626 1,227
Total $ 12,269 $ 14,031