Loans (Past Due Loans) (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		$ 13,622	$ 20,075
Current loans		3,666,738	3,353,996
Total loans	[1]	3,680,360	3,374,071
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		1,080	4,960
Current loans		1,391,328	1,205,535
Total loans	[2]	1,392,408	1,210,495
Commercial & Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		0	4,076
Current loans		620,704	608,258
Total loans	[3]	620,704	612,334
Total Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		1,080	9,036
Current loans		2,012,032	1,813,793
Total loans		2,013,112	1,822,829
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		10,520	7,855
Current loans		1,349,867	1,219,393
Total loans	[4]	1,360,387	1,227,248
Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		1,989	3,141
Current loans		278,637	289,326
Total loans		280,626	292,467
Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		33	43
Current loans		26,202	31,484
Total loans	[5]	26,235	31,527
Total Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		2,022	3,184
Current loans		304,839	320,810
Total loans		306,861	323,994
30-59
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		7,787	8,304
30-59 | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		155	6
30-59 | Commercial & Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		0	3,793
30-59 | Total Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		155	3,799
30-59 | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		6,318	1,678
30-59 | Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		1,281	2,798
30-59 | Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		33	29
30-59 | Total Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		1,314	2,827
60-89
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		3,774	2,351
60-89 | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		925	0
60-89 | Commercial & Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		0	2
60-89 | Total Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		925	2
60-89 | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		2,693	2,274
60-89 | Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		156	75
60-89 | Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		0	0
60-89 | Total Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		156	75
Over 90
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		2,061	9,420
Over 90 | Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		0	4,954
Over 90 | Commercial & Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		0	281
Over 90 | Total Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		0	5,235
Over 90 | Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		1,509	3,903
Over 90 | Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		552	268
Over 90 | Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		0	14
Over 90 | Total Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past due loans		$ 552	$ 282

[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.