Loans (Summary of Loans) (Details) - USD ($) $ in Thousands		Jun. 30, 2017	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[1]	$ 3,200,100	$ 3,234,371
Percent of Total Loans	[1]	100.00%	100.00%
Commercial Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 1,009,096	$ 1,074,186
Commercial Construction & Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		112,177	121,371
Commercial & Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		577,116	576,109
Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		1,143,416	1,094,824
Homeowner Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		24,689	27,924
Home Equity Lines [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		263,934	264,200
Home Equity Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		35,173	37,272
Other Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		34,499	38,485
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 1,698,389	$ 1,771,666
Percent of Total Loans		53.00%	55.00%
Commercial [Member] | Commercial Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[2]	$ 1,009,096	$ 1,074,186
Percent of Total Loans	[2]	32.00%	33.00%
Commercial [Member] | Commercial Construction & Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[3]	$ 112,177	$ 121,371
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]	$ 577,116	$ 576,109
Percent of Total Loans	[4]	17.00%	18.00%
Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 1,168,105	$ 1,122,748
Percent of Total Loans		37.00%	35.00%
Residential Real Estate [Member] | Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 1,143,416	$ 1,094,824
Percent of Total Loans		36.00%	34.00%
Residential Real Estate [Member] | Homeowner Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 24,689	$ 27,924
Percent of Total Loans		1.00%	1.00%
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 333,606	$ 339,957
Percent of Total Loans		10.00%	10.00%
Consumer [Member] | Home Equity Lines [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 263,934	$ 264,200
Percent of Total Loans		8.00%	8.00%
Consumer [Member] | Home Equity Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans		$ 35,173	$ 37,272
Percent of Total Loans		1.00%	1.00%
Consumer [Member] | Other Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	[5]	$ 34,499	$ 38,485
Percent of Total Loans	[5]	1.00%	1.00%

[1] Includes net unamortized loan origination costs of $3.7 million and $3.0 million, respectively, at June 30, 2017 and December 31, 2016 and net unamortized premiums on purchased loans of $854 thousand and $783 thousand, respectively, at June 30, 2017 and December 31, 2016.

[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.