Retirement Benefits (Schedule Of Amounts Recognized In Consolidated Balance Sheets) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Noncurrent liability	$ 9,204	$ 7,877
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Current liability	2	8
Noncurrent liability	6,434	5,187
Amounts recognized in the consolidated balance sheets	6,436	5,195
Retiree Medical And Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Current liability	147	173
Noncurrent liability	2,770	2,690
Amounts recognized in the consolidated balance sheets	$ 2,917	$ 2,863