Employee Benefits And Deferred Compensation Plans (Schedule Of Weighted Average Asset Allocation) (Details) - Pension Plan [Member] |
Dec. 31, 2020 |
Dec. 31, 2019 |
---|---|---|
Defined Benefit Plan Disclosure [Line Items] | ||
Weighted average plan asset allocations | 100.00% | 100.00% |
Equity Mutual Funds [Member] | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Weighted average plan asset allocations | 30.83% | 27.28% |
Fixed Income Mutual Funds [Member] | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Weighted average plan asset allocations | 67.59% | 71.59% |
Cash/Short-Term Investments [Member] | ||
Defined Benefit Plan Disclosure [Line Items] | ||
Weighted average plan asset allocations | 1.58% | 1.13% |