Allowance for Credit Losses - Recorded Investment in Loans and Leases (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	$ 10,337
Total loans and leases, net of unearned income and deferred costs and fees	5,424,285	$ 4,917,550
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	621
Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment	$ 8,157
Originated
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment		19,385
Collectively evaluated for impairment		4,681,661
Total loans and leases, net of unearned income and deferred costs and fees		4,701,046
Originated | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment		2,110
Collectively evaluated for impairment		966,875
Total loans and leases, net of unearned income and deferred costs and fees		968,985
Originated | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment		13,496
Collectively evaluated for impairment		2,283,152
Total loans and leases, net of unearned income and deferred costs and fees		2,296,648
Originated | Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment		3,779
Collectively evaluated for impairment		1,340,687
Total loans and leases, net of unearned income and deferred costs and fees		1,344,466
Originated | Consumer and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment		0
Collectively evaluated for impairment		73,625
Total loans and leases, net of unearned income and deferred costs and fees		73,625
Originated | Finance Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment		0
Collectively evaluated for impairment		17,322
Total loans and leases, net of unearned income and deferred costs and fees		17,322
Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment		2,830
Loans acquired with deteriorated credit quality		9,149
Collectively evaluated for impairment		208,170
Total loans and leases, net of unearned income and deferred costs and fees		220,149
Acquired | Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment		2
Loans acquired with deteriorated credit quality		173
Collectively evaluated for impairment		38,901
Total loans and leases, net of unearned income and deferred costs and fees		39,076
Acquired | Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment		714
Loans acquired with deteriorated credit quality		5,674
Collectively evaluated for impairment		140,529
Total loans and leases, net of unearned income and deferred costs and fees		146,917
Acquired | Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment		2,114
Loans acquired with deteriorated credit quality		3,302
Collectively evaluated for impairment		27,955
Total loans and leases, net of unearned income and deferred costs and fees		33,371
Acquired | Consumer and other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment		0
Loans acquired with deteriorated credit quality		0
Collectively evaluated for impairment		785
Total loans and leases, net of unearned income and deferred costs and fees		785
Acquired | Finance Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Individually evaluated for impairment		0
Loans acquired with deteriorated credit quality		0
Collectively evaluated for impairment		0
Total loans and leases, net of unearned income and deferred costs and fees		$ 0