Pension And Other Postretirement Plans (Estimated Future Benefit Payments) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
2012	$ 271
2013	282
2014	277
2015	279
2016	274
Years 2017 - 2021	1,361
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
2012	147
2013	150
2014	156
2015	163
2016	170
Years 2017 - 2021	971
Other Postretirement-Subsidy Receipts [Member]
Defined Benefit Plan Disclosure [Line Items]
2012	13
2013	15
2014	16
2015	17
2016	18
Years 2017 - 2021	$ 105