Loans (Summary of Loans) (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[1]	$ 3,680,360	$ 3,374,071
Percent of total loans	[1]	100.00%	100.00%
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[2]	$ 1,392,408	$ 1,210,495
Percent of total loans	[2]	38.00%	36.00%
Commercial & Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[3]	$ 620,704	$ 612,334
Percent of total loans	[3]	17.00%	18.00%
Total Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 2,013,112	$ 1,822,829
Percent of total loans		55.00%	54.00%
Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[4]	$ 1,360,387	$ 1,227,248
Percent of total loans	[4]	37.00%	36.00%
Home Equity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 280,626	$ 292,467
Percent of total loans		8.00%	9.00%
Other Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[5]	$ 26,235	$ 31,527
Percent of total loans	[5]	0.00%	1.00%
Total Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 306,861	$ 323,994
Percent of total loans		8.00%	10.00%

[1] Includes net unamortized loan origination costs of $4.7 million and $3.8 million, respectively, at December 31, 2018 and 2017 and net unamortized premiums on purchased loans of $703 thousand and $878 thousand, respectively, at December 31, 2018 and 2017.

[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.