Employee Benefit Plans (Summary Of Assets Segregated By Level Of Valuation Inputs Within The Fair Value Hierarchy) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Total	$ 12,629	$ 11,884	$ 12,041
Level 1
Defined Benefit Plan Disclosure [Line Items]
Total	10,247	6,866
Level 2
Defined Benefit Plan Disclosure [Line Items]
Total	2,382	5,018
Level 3
Defined Benefit Plan Disclosure [Line Items]
Total	0	0
Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Total	146	79
Cash and Cash Equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total	146	79
Cash and Cash Equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total	0	0
Cash and Cash Equivalents | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total	0	0
US Government Agencies Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Total	100
US Government Agencies Debt Securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total	0
US Government Agencies Debt Securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total	100
US Government Agencies Debt Securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total
Common stocks
Defined Benefit Plan Disclosure [Line Items]
Total	10,101	6,787
Common stocks | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total	10,101	6,787
Common stocks | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total	0	0
Common stocks | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total	0	0
Corporate Bond Securities
Defined Benefit Plan Disclosure [Line Items]
Total	2,282	5,018
Corporate Bond Securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total	0	0
Corporate Bond Securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total	2,282	5,018
Corporate Bond Securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total	$ 0	$ 0