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	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Commitments and Contingencies [Line Items]
Balance at the beginning of the period	$ 80	$ 28
Provision for termite damage claims	12	6
Cash payments	(11)	(11)
Balance at the end of the period	$ 81	$ 24