Commitments And Contingencies (Schedule Of Reconciliation Of Beginning And Ending Accrued Litigated Claims And Non-Litigated Claims) (Details) - Litigated Claims And Non-Litigated Claims [Member] - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Commitments and Contingencies [Line Items]
Balance at the beginning of the period	$ 80	$ 28
Provision for termite damage claims	27	16
Cash payments	(24)	(23)
Balance at the end of the period	$ 83	$ 21