Employee Benefits And Deferred Compensation Plans (Schedule of Allocation Of Plan Assets) (Details) - Pension Plans [Member] - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Plan assets	$ 4,266	$ 4,067	$ 4,201
Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	4,266	4,067
Cash [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets		44
Mutual Funds, Money Market [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	78	275
Fixed Income Mutual Funds [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	1,288	394
Equities, Small Cap [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	307	375
Equities, Large Cap [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	1,008
Equities, Real Estate [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	101	234
Equities, International Large Cap [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	923	757
Equities, International Small Cap [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	201
Equities, Emerging Markets [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	254	388
Equities, Currency [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets		177
Equities, Commodity [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	$ 106	35
Equities, Bank Loans [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets		187
Exchange-Traded Funds (ETFs), Large Cap [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets		844
Exchange-Traded Funds (ETFs), Mid Cap [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets		$ 357