Loans (Summary of Loans) (Details) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[1]	$ 3,234,371	$ 3,013,127
Percent of total loans	[1]	100.00%	100.00%
Commercial Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 1,074,186	$ 931,953
Commercial Construction & Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		121,371	122,297
Commercial & Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		576,109	600,297
Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		1,094,824	984,437
Homeowner Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		27,924	29,118
Home Equity Lines [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		264,200	255,565
Home Equity Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		37,272	46,649
Other Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		38,485	42,811
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 1,771,666	$ 1,654,547
Percent of total loans		55.00%	55.00%
Commercial [Member] | Commercial Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[2]	$ 1,074,186	$ 931,953
Percent of total loans	[2]	33.00%	31.00%
Commercial [Member] | Commercial Construction & Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[3]	$ 121,371	$ 122,297
Percent of total loans	[3]	4.00%	4.00%
Commercial [Member] | Commercial & Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[4]	$ 576,109	$ 600,297
Percent of total loans	[4]	18.00%	20.00%
Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 1,122,748	$ 1,013,555
Percent of total loans		35.00%	34.00%
Residential Real Estate [Member] | Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 1,094,824	$ 984,437
Percent of total loans		34.00%	33.00%
Residential Real Estate [Member] | Homeowner Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 27,924	$ 29,118
Percent of total loans		1.00%	1.00%
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 339,957	$ 345,025
Percent of total loans		10.00%	11.00%
Consumer [Member] | Home Equity Lines [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 264,200	$ 255,565
Percent of total loans		8.00%	8.00%
Consumer [Member] | Home Equity Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 37,272	$ 46,649
Percent of total loans		1.00%	2.00%
Consumer [Member] | Other Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[5]	$ 38,485	$ 42,811
Percent of total loans	[5]	1.00%	1.00%

[1] Includes net unamortized loan origination costs of $3.0 million and $2.6 million, respectively, and net unamortized premiums on purchased loans of $783 thousand and $84 thousand, respectively, at December 31, 2016 and 2015.

[2] Loans primarily secured by income producing property.

[3] Loans for construction of commercial properties, loans to developers for construction of residential properties and loans for land development.

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

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