Retirement Plans And Other Postretirement Benefits (Schedule Of Fair Value Measurements Of Plan Assets Using Significant Unobservable Inputs (Level 3), Reconciliation Of Balances) (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Estimated Value Of Asset Contracts With Insurance Companies	$ 8,840