Employee Benefit Plans (Summary Of Assets Segregated By Level Of Valuation Inputs Within The Fair Value Hierarchy) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Total	$ 11,884	$ 12,041	$ 16,360
Level 1
Defined Benefit Plan Disclosure [Line Items]
Total	6,866	12,041
Level 2
Defined Benefit Plan Disclosure [Line Items]
Total	5,018	0
Level 3
Defined Benefit Plan Disclosure [Line Items]
Total	0	0
Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Total	79	12,041
Cash and Cash Equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total	79	12,041
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
Common stocks
Defined Benefit Plan Disclosure [Line Items]
Total	6,787
Common stocks | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total	6,787
Common stocks | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total	0
Common stocks | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total	0
Corporate Bond Securities
Defined Benefit Plan Disclosure [Line Items]
Total	5,018
Corporate Bond Securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Total	0
Corporate Bond Securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Total	5,018
Corporate Bond Securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Total	$ 0