Loans and Loans Held for Sale - Composition of Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Composition of the loans
Portfolio loans, net of unearned income	$ 5,935,452	$ 5,946,648
Loans held for sale	2,706	2,371
Total Loans	5,938,158	5,949,019
Commercial real estate
Composition of the loans
Portfolio loans, net of unearned income	2,901,625	2,921,832
Total Loans	2,901,625	2,921,832
Commercial and industrial
Composition of the loans
Portfolio loans, net of unearned income	1,513,007	1,493,416
Total Loans	1,513,007	1,493,416
Commercial construction
Composition of the loans
Portfolio loans, net of unearned income	245,658	257,197
Total Loans	245,658	257,197
Residential mortgage
Composition of the loans
Total Loans	729,914	726,679
Home equity
Composition of the loans
Total Loans	463,566	471,562
Installment and other consumer
Composition of the loans
Total Loans	70,960	67,546
Consumer construction
Composition of the loans
Total Loans	10,722	8,416
Commercial
Composition of the loans
Portfolio loans, net of unearned income	4,660,290	4,672,445
Commercial \| Commercial real estate
Composition of the loans
Portfolio loans, net of unearned income	2,901,625	2,921,832
Commercial \| Commercial and industrial
Composition of the loans
Portfolio loans, net of unearned income	1,513,007	1,493,416
Commercial \| Commercial construction
Composition of the loans
Portfolio loans, net of unearned income	245,658	257,197
Consumer
Composition of the loans
Portfolio loans, net of unearned income	1,275,162	1,274,203
Consumer \| Residential mortgage
Composition of the loans
Portfolio loans, net of unearned income	729,914	726,679
Consumer \| Home equity
Composition of the loans
Portfolio loans, net of unearned income	463,566	471,562
Consumer \| Installment and other consumer
Composition of the loans
Portfolio loans, net of unearned income	70,960	67,546
Consumer \| Consumer construction
Composition of the loans
Portfolio loans, net of unearned income	$ 10,722	$ 8,416

Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5074-111524

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Amount, after allowance for bad debt, of loan receivables held-for-sale that are not part of a disposal group. Excludes loans and leases covered under loss sharing agreements and loans classified as debt securities.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes loans held for sale. Excludes loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
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