Risk Management (Schedule Of Largest Notional Amounts Of The Positions To Buy Or Sell Foreign Currency) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Foreign Currency Contracts
Notional amount of foreign currency derivatives	$ 360	$ 524
Chinese Renminbi
Foreign Currency Contracts
Notional amount of foreign currency derivatives	(144)	(283)
Euro
Foreign Currency Contracts
Notional amount of foreign currency derivatives	50	8
Israeli Shekel
Foreign Currency Contracts
Notional amount of foreign currency derivatives	(41)	8
Japanese Yen
Foreign Currency Contracts
Notional amount of foreign currency derivatives	32	46
Australian Dollar
Foreign Currency Contracts
Notional amount of foreign currency derivatives	$ (16)	$ (6)