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, 2012
Pension Benefits [Member]
Schedule Of Gross Benefit Payments That Are Expected To Be Paid For The Domestic And International Plans [Line Items]
2013	$ 208
2014	188
2015	196
2016	198
2017	201
2018-2022	1,101
Postretirement Benefits [Member]
Schedule Of Gross Benefit Payments That Are Expected To Be Paid For The Domestic And International Plans [Line Items]
2013	73
2014	77
2015	80
2016	83
2017	85
2018-2022	456
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]
2013	6
2014	6
2015	7
2016	7
2017	7
2018-2022	$ 42