Loans (Past Due Loans) (Details) - USD ($) $ in Thousands		Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Total past due		$ 16,475	$ 15,689
Current		4,073,921	3,877,310
Total loans	[1]	4,090,396	3,892,999
30-59
Financing Receivable, Past Due [Line Items]
Total past due		7,877	6,418
60-89
Financing Receivable, Past Due [Line Items]
Total past due		1,301	2,884
Over 90
Financing Receivable, Past Due [Line Items]
Total past due		7,297	6,387
Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Total past due		1,275	1,433
Current		1,616,745	1,546,139
Total loans	[2]	1,618,020	1,547,572
Commercial Real Estate | 30-59
Financing Receivable, Past Due [Line Items]
Total past due		825	830
Commercial Real Estate | 60-89
Financing Receivable, Past Due [Line Items]
Total past due		0	0
Commercial Real Estate | Over 90
Financing Receivable, Past Due [Line Items]
Total past due		450	603
Commercial & Industrial
Financing Receivable, Past Due [Line Items]
Total past due		310	1
Current		654,847	585,288
Total loans	[3]	655,157	585,289
Commercial & Industrial | 30-59
Financing Receivable, Past Due [Line Items]
Total past due		20	1
Commercial & Industrial | 60-89
Financing Receivable, Past Due [Line Items]
Total past due		0	0
Commercial & Industrial | Over 90
Financing Receivable, Past Due [Line Items]
Total past due		290	0
Total Commercial
Financing Receivable, Past Due [Line Items]
Total past due		1,585	1,434
Current		2,271,592	2,131,427
Total loans		2,273,177	2,132,861
Total Commercial | 30-59
Financing Receivable, Past Due [Line Items]
Total past due		845	831
Total Commercial | 60-89
Financing Receivable, Past Due [Line Items]
Total past due		0	0
Total Commercial | Over 90
Financing Receivable, Past Due [Line Items]
Total past due		740	603
Residential Real Estate
Financing Receivable, Past Due [Line Items]
Total past due		12,293	11,429
Current		1,498,179	1,437,661
Total loans	[4]	1,510,472	1,449,090
Residential Real Estate | 30-59
Financing Receivable, Past Due [Line Items]
Total past due		5,410	4,574
Residential Real Estate | 60-89
Financing Receivable, Past Due [Line Items]
Total past due		1,197	2,155
Residential Real Estate | Over 90
Financing Receivable, Past Due [Line Items]
Total past due		5,686	4,700
Home Equity
Financing Receivable, Past Due [Line Items]
Total past due		2,482	2,696
Current		284,652	288,178
Total loans		287,134	290,874
Home Equity | 30-59
Financing Receivable, Past Due [Line Items]
Total past due		1,596	971
Home Equity | 60-89
Financing Receivable, Past Due [Line Items]
Total past due		103	729
Home Equity | Over 90
Financing Receivable, Past Due [Line Items]
Total past due		783	996
Other
Financing Receivable, Past Due [Line Items]
Total past due		115	130
Current		19,498	20,044
Total loans	[5]	19,613	20,174
Other | 30-59
Financing Receivable, Past Due [Line Items]
Total past due		26	42
Other | 60-89
Financing Receivable, Past Due [Line Items]
Total past due		1	0
Other | Over 90
Financing Receivable, Past Due [Line Items]
Total past due		88	88
Total Consumer
Financing Receivable, Past Due [Line Items]
Total past due		2,597	2,826
Current		304,150	308,222
Total loans		306,747	311,048
Total Consumer | 30-59
Financing Receivable, Past Due [Line Items]
Total past due		1,622	1,013
Total Consumer | 60-89
Financing Receivable, Past Due [Line Items]
Total past due		104	729
Total Consumer | Over 90
Financing Receivable, Past Due [Line Items]
Total past due		$ 871	$ 1,084

[1] Includes net unamortized loan origination costs of $5.2 million and $5.3 million, respectively, at March 31, 2020 and December 31, 2019 and net unamortized premiums on purchased loans of $724 thousand and $995 thousand, respectively, at March 31, 2020 and December 31, 2019.

[2] Commercial real estate (“CRE”) 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] Commercial and industrial (“C&I”) consists of loans to businesses and individuals, a substantial portion of which are fully or partially collateralized by real estate.

[4] Residential real estate consists of mortgage and homeowner construction loans secured by one- to four-family residential properties.

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