Employee Retirement Plans (Estimated Future Benefit Payments, And Gross Amount Of Annual Medicare Part D Subsidy Expected To Be Received) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011
Pension Benefits [Member]
Schedule Of Gross Benefit Payments That Are Expected To Be Paid For The Domestic And International Plans [Line Items]
2012	$ 188
2013	188
2014	190
2015	197
2016	198
2017-2021	1,085
Postretirement Benefits [Member]
Schedule Of Gross Benefit Payments That Are Expected To Be Paid For The Domestic And International Plans [Line Items]
2012	79
2013	84
2014	88
2015	91
2016	94
2017-2021	509
Expected Federal Subsidy Payments [Member] | Postretirement Benefits [Member]
Schedule Of Gross Benefit Payments That Are Expected To Be Paid For The Domestic And International Plans [Line Items]
2012	6
2013	7
2014	7
2015	8
2016	8
2017-2021	$ 47