Postretirement Plans (Schedule Of Benefit Payments And Receipts) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011
Qualified Defined Benefit Pension Plans [Member]
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Payments in 2012	$ 1,760
Payments in 2013	1,830
Payments in 2014	1,910
Payments in 2015	1,990
Payments in 2016	2,080
Payments in years 2017 - 2021	12,120
Retiree Medical And Life Insurance Plans [Member]
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Payments in 2012	240
Payments in 2013	250
Payments in 2014	260
Payments in 2015	260
Payments in 2016	270
Payments in years 2017 - 2021	$ 1,240