Pension And Other Postretirement Plans (Amounts Recognized In Balance Sheet And Other Comprehensive Income (Loss)) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Noncurrent asset	$ 31	$ 32
Current liability	(9)	(10)
Noncurrent liability	(1,862)	(1,473)
Total liability	(1,840)	(1,451)
Net actuarial gain (loss)	(231)	226
Prior service credit (cost)	3	18
Total accumulated other comprehensive income (loss)	(228)	244
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Current liability	(76)	(92)
Noncurrent liability	(2,407)	(2,344)
Total liability	(2,483)	(2,436)
Net actuarial gain (loss)	33	24
Prior service credit (cost)	(2)
Total accumulated other comprehensive income (loss)	$ 31	$ 24