Basis Of Presentation (Schedule Of Impact Of ASC 326) (Details) - USD ($)	Mar. 31, 2020	Jan. 01, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Allowance for credit losses on loans	$ 34,105,000		$ 29,289,000	$ 30,199,000	$ 30,838,000
Allowance for credit losses on off-balance sheet credit exposures			175,000
Commercial And Industrial [Member]
Allowance for credit losses on loans	1,931,000		1,493,000	1,047,000	1,158,000
Consumer And Other [Member]
Allowance for credit losses on loans	7,000		13,000	42,000	49,000
Multifamily Loan [Member] | Commercial Mortgages [Member]
Allowance for credit losses on loans	8,647,000		7,151,000	6,435,000	5,851,000
Other Loan [Member] | Commercial Mortgages [Member]
Allowance for credit losses on loans	3,792,000		3,498,000	3,517,000	3,783,000
Owner-occupied Loan [Member] | Commercial Mortgages [Member]
Allowance for credit losses on loans	1,782,000		921,000	685,000	743,000
Closed-end [Member] | Residential Mortgages [Member]
Allowance for credit losses on loans	17,459,000		15,698,000	18,071,000	18,844,000
Revolving Home Equity [Member] | Residential Mortgages [Member]
Allowance for credit losses on loans	$ 487,000		515,000	$ 402,000	$ 410,000
As Reported Under ASC 326 [Member]
Allowance for credit losses on loans		$ 32,177,000	32,177,000
Allowance for credit losses on off-balance sheet credit exposures		605,000
As Reported Under ASC 326 [Member] | Commercial And Industrial [Member]
Allowance for credit losses on loans		1,249,000	1,249,000
As Reported Under ASC 326 [Member] | Consumer And Other [Member]
Allowance for credit losses on loans		5,000	5,000
As Reported Under ASC 326 [Member] | Multifamily Loan [Member] | Commercial Mortgages [Member]
Allowance for credit losses on loans		8,210,000	8,210,000
As Reported Under ASC 326 [Member] | Other Loan [Member] | Commercial Mortgages [Member]
Allowance for credit losses on loans		3,451,000	3,451,000
As Reported Under ASC 326 [Member] | Owner-occupied Loan [Member] | Commercial Mortgages [Member]
Allowance for credit losses on loans		1,699,000	1,699,000
As Reported Under ASC 326 [Member] | Closed-end [Member] | Residential Mortgages [Member]
Allowance for credit losses on loans		17,054,000	17,054,000
As Reported Under ASC 326 [Member] | Revolving Home Equity [Member] | Residential Mortgages [Member]
Allowance for credit losses on loans		509,000	$ 509,000
Impact Of Adopting ASU 2016-13 [Member]
Allowance for credit losses on loans		2,888,000
Allowance for credit losses on off-balance sheet credit exposures		430,000
Impact Of Adopting ASU 2016-13 [Member] | Commercial And Industrial [Member]
Allowance for credit losses on loans		(244,000)
Impact Of Adopting ASU 2016-13 [Member] | Consumer And Other [Member]
Allowance for credit losses on loans		(8,000)
Impact Of Adopting ASU 2016-13 [Member] | Multifamily Loan [Member] | Commercial Mortgages [Member]
Allowance for credit losses on loans		1,059,000
Impact Of Adopting ASU 2016-13 [Member] | Other Loan [Member] | Commercial Mortgages [Member]
Allowance for credit losses on loans		(47,000)
Impact Of Adopting ASU 2016-13 [Member] | Owner-occupied Loan [Member] | Commercial Mortgages [Member]
Allowance for credit losses on loans		778,000
Impact Of Adopting ASU 2016-13 [Member] | Closed-end [Member] | Residential Mortgages [Member]
Allowance for credit losses on loans		1,356,000
Impact Of Adopting ASU 2016-13 [Member] | Revolving Home Equity [Member] | Residential Mortgages [Member]
Allowance for credit losses on loans		$ (6,000)