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	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Commitments and Contingencies [Line Items]
Balance at the beginning of the period	$ 72	$ 80
Provision for termite damage claims	47	41
Cash payments	(49)	(42)
Balance at the end of the period	$ 69	$ 79