Commitments and Contingencies (Schedule Of Reconciliation Of Beginning And Ending Accrued Self-Insured Claims) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2016	Jun. 30, 2015
Commitments and Contingencies [Line Items]
Increase (Decrease) in Self Insurance Reserve	$ 23	$ 23
Accrued Self-Insured Claims, Net [Member]
Commitments and Contingencies [Line Items]
Balance at the beginning of the period		114	$ 104
Provision for self-insured claims		44	20
Cash payments		(24)	(14)
Balance at the end of the period	$ 133	$ 133	$ 110