Loans (Summary of Loans) (Details) - USD ($) $ in Thousands		Sep. 30, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[1]	$ 3,778,106	$ 3,680,360
Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[2]	1,517,320	1,392,408
Commercial & Industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[3]	566,426	620,704
Total Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		2,083,746	2,013,112
Residential Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[4]	1,378,518	1,360,387
Home Equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		294,250	280,626
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[5]	21,592	26,235
Total Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 315,842	$ 306,861

[1] Includes net unamortized loan origination costs of $5.7 million and $4.7 million, respectively, at September 30, 2019 and December 31, 2018 and net unamortized premiums on purchased loans of $575 thousand and $703 thousand, respectively, at September 30, 2019 and December 31, 2018.

[2] Consists of commercial mortgages primarily secured by income-producing property, as well as construction and development loans. Construction and development loans are made to businesses for land development or the on-site construction of industrial, commercial, or residential buildings.

[3] Consists of loans to businesses and individuals, a substantial portion of which are fully or partially collateralized by real estate.

[4] Consists of mortgage and homeowner construction loans secured by one- to four-family residential properties.

[5] Consists of loans to individuals secured by general aviation aircraft and other personal installment loans.