Allowance for Loan and Lease Losses (Details 2) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 4,301,931	$ 4,261,979
Commercial and industrial, total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1,054,725	1,044,619
Commercial real estate, total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1,935,165	1,920,841
Residential real estate, total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	1,239,008	1,219,815
Consumer and other, total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	57,418	60,054
Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	15,615	16,650
Originated Loans and Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	12,439	12,954
Collectively evaluated for impairment	3,914,112	3,854,914
Total	3,926,551	3,867,868
Originated Loans and Leases | Commercial and industrial, total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	241	635
Collectively evaluated for impairment	975,128	964,667
Total	975,369	965,302
Originated Loans and Leases | Commercial real estate, total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	8,706	8,812
Collectively evaluated for impairment	1,691,351	1,661,221
Total	1,700,057	1,670,033
Originated Loans and Leases | Residential real estate, total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	3,492	3,507
Collectively evaluated for impairment	1,175,401	1,153,148
Total	1,178,893	1,156,655
Originated 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	56,617	59,228
Total	56,617	59,228
Originated Loans and Leases | Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	15,615	16,650
Total	15,615	16,650
Total Acquired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	3,293	5,625
Loans acquired with deteriorated credit quality	20,027	22,517
Collectively evaluated for impairment	352,060	365,969
Total	375,380	394,111
Total Acquired Loans | Commercial and industrial, total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	170	172
Loans acquired with deteriorated credit quality	372	448
Collectively evaluated for impairment	78,814	78,697
Total	79,356	79,317
Total Acquired Loans | Commercial real estate, total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	1,672	4,081
Loans acquired with deteriorated credit quality	12,497	14,368
Collectively evaluated for impairment	220,939	232,359
Total	235,108	250,808
Total Acquired Loans | Residential real estate, total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	1,451	1,372
Loans acquired with deteriorated credit quality	7,158	7,701
Collectively evaluated for impairment	51,506	54,087
Total	60,115	63,160
Total Acquired Loans | 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	801	826
Total	801	826
Total Acquired Loans | Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	0	0
Total Acquired Loans | Covered Loans
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	0	0
Total	$ 0	$ 0