Loans (Collateral Dependent Individually Analyzed Loans) (Details) - USD ($) $ in Thousands		Mar. 31, 2021		Dec. 31, 2020
Loans and Leases Receivable Disclosure [Line Items]
Collateral dependent loans	[1]	$ 4,194,666		$ 4,195,990
Collateral Dependent Individually Analyzed
Loans and Leases Receivable Disclosure [Line Items]
Collateral dependent loans		6,942		8,444
Related allowance		183		221
Commercial Real Estate
Loans and Leases Receivable Disclosure [Line Items]
Collateral dependent loans	[2]	1,618,540		1,633,024
Commercial Real Estate | Collateral Dependent Individually Analyzed
Loans and Leases Receivable Disclosure [Line Items]
Collateral dependent loans		958	[3]	1,792
Related allowance		0	[3]	0
Commercial & Industrial
Loans and Leases Receivable Disclosure [Line Items]
Collateral dependent loans	[4]	840,585		817,408
Commercial & Industrial | Collateral Dependent Individually Analyzed
Loans and Leases Receivable Disclosure [Line Items]
Collateral dependent loans		398	[5]	451
Related allowance		0	[5]	0
Total Commercial
Loans and Leases Receivable Disclosure [Line Items]
Collateral dependent loans		2,459,125		2,450,432
Total Commercial | Collateral Dependent Individually Analyzed
Loans and Leases Receivable Disclosure [Line Items]
Collateral dependent loans		1,356		2,243
Related allowance		0		0
Residential Real Estate
Loans and Leases Receivable Disclosure [Line Items]
Collateral dependent loans	[6]	1,457,490		1,467,312
Residential Real Estate | Collateral Dependent Individually Analyzed
Loans and Leases Receivable Disclosure [Line Items]
Collateral dependent loans		5,332	[7]	5,947
Related allowance		0	[7]	38
Home Equity
Loans and Leases Receivable Disclosure [Line Items]
Collateral dependent loans		256,799		259,185
Home Equity | Collateral Dependent Individually Analyzed
Loans and Leases Receivable Disclosure [Line Items]
Collateral dependent loans		254	[7]	254
Related allowance		183	[7]	183
Other
Loans and Leases Receivable Disclosure [Line Items]
Collateral dependent loans	[8]	21,252		19,061
Other | Collateral Dependent Individually Analyzed
Loans and Leases Receivable Disclosure [Line Items]
Collateral dependent loans		0		0
Related allowance		0		0
Total Consumer
Loans and Leases Receivable Disclosure [Line Items]
Collateral dependent loans		278,051		278,246
Total Consumer | Collateral Dependent Individually Analyzed
Loans and Leases Receivable Disclosure [Line Items]
Collateral dependent loans		254		254
Related allowance		$ 183		$ 183

[1] Includes net unamortized loan origination fees of $223 thousand at March 31, 2021 and net unamortized loan origination costs of $1.5 million, at December 31, 2020 and net unamortized premiums on purchased loans of $653 thousand and $787 thousand, respectively, at March 31, 2021 and December 31, 2020.

[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] Secured by income-producing property.

[4] Commercial and industrial (“C&I”) consists of loans to businesses and individuals, a portion of which are fully or partially collateralized by real estate. C&I also includes $228.6 million and $199.8 million, respectively, of PPP loans as of March 31, 2021 and December 31, 2020.

[5] Secured by business assets.

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

[7] Secured by one- to four-family residential properties.

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