Loans (Risk Ratings) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	$ 3,188,249	$ 3,263,399
Commercial And Industrial [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	103,879	98,785
Commercial And Industrial [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	100,095	97,684
Commercial And Industrial [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	3,493	667
Commercial And Industrial [Member] | Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	291	434
Commercial And Industrial [Member] | Internal Investment Grade [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	103,879	98,785
Residential Mortgages [Member] | Closed-end [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,621,419	1,809,651
Residential Mortgages [Member] | Revolving Home Equity [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	59,231	67,710
Residential Mortgages [Member] | Pass [Member] | Closed-end [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,619,034	1,807,525
Residential Mortgages [Member] | Pass [Member] | Revolving Home Equity [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	58,816	66,718
Residential Mortgages [Member] | Watch [Member] | Closed-end [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	306	312
Residential Mortgages [Member] | Watch [Member] | Revolving Home Equity [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	415
Residential Mortgages [Member] | Special Mention [Member] | Closed-end [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	890
Residential Mortgages [Member] | Special Mention [Member] | Revolving Home Equity [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans		249
Residential Mortgages [Member] | Substandard [Member] | Closed-end [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,189	1,814
Residential Mortgages [Member] | Substandard [Member] | Revolving Home Equity [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans		743
Residential Mortgages [Member] | Internal Investment Grade [Member] | Closed-end [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,621,419	1,809,651
Residential Mortgages [Member] | Internal Investment Grade [Member] | Revolving Home Equity [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	59,231	67,710
Commercial Mortgages [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,401,289	1,281,295
Commercial Mortgages [Member] | Multifamily Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	835,013	756,714
Commercial Mortgages [Member] | Other Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	447,484	433,330
Commercial Mortgages [Member] | Owner-occupied Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	118,792	91,251
Commercial Mortgages [Member] | Pass [Member] | Multifamily Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	831,360	756,714
Commercial Mortgages [Member] | Pass [Member] | Other Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	437,655	417,838
Commercial Mortgages [Member] | Pass [Member] | Owner-occupied Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	113,534	85,710
Commercial Mortgages [Member] | Watch [Member] | Other Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans		14,194
Commercial Mortgages [Member] | Watch [Member] | Owner-occupied Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans		1,090
Commercial Mortgages [Member] | Special Mention [Member] | Multifamily Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	3,653
Commercial Mortgages [Member] | Special Mention [Member] | Other Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	9,829	1,298
Commercial Mortgages [Member] | Special Mention [Member] | Owner-occupied Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	4,757	3,911
Commercial Mortgages [Member] | Substandard [Member] | Owner-occupied Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	501	540
Commercial Mortgages [Member] | Internal Investment Grade [Member] | Multifamily Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	835,013	756,714
Commercial Mortgages [Member] | Internal Investment Grade [Member] | Other Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	447,484	433,330
Commercial Mortgages [Member] | Internal Investment Grade [Member] | Owner-occupied Loan [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	118,792	91,251
Consumer And Other [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	2,431	5,958
Consumer And Other [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,644	4,958
Consumer And Other [Member] | Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	268	324
Consumer And Other [Member] | Internal Investment Grade [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,912	5,282
Residential Mortgages, Home Equity Lines, And Other Consumer Loans [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,679,494	1,879,201
Residential Mortgages, Home Equity Lines, And Other Consumer Loans [Member] | Watch [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	721	312
Residential Mortgages, Home Equity Lines, And Other Consumer Loans [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	890	249
Residential Mortgages, Home Equity Lines, And Other Consumer Loans [Member] | Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,457	2,881
Residential Mortgages, Home Equity Lines, And Other Consumer Loans [Member] | Internal Investment Grade [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,682,562	1,882,643
Commercial And Industrial Loans And Commercial Real Estate Loans [Member] | Pass [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	1,482,644	1,357,946
Commercial And Industrial Loans And Commercial Real Estate Loans [Member] | Watch [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans		15,284
Commercial And Industrial Loans And Commercial Real Estate Loans [Member] | Special Mention [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	21,732	5,876
Commercial And Industrial Loans And Commercial Real Estate Loans [Member] | Substandard [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	792	974
Commercial And Industrial Loans And Commercial Real Estate Loans [Member] | Internal Investment Grade [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Loans	$ 1,505,168	$ 1,380,080