Employee Benefit Plans (Details) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Pension Contributions			$ 50	$ 26
Defined Contribution Benefit Plan Contributions By Employer			5	5
Pension Plans Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan Service Cost	3	3	10	8
Defined Benefit Plan Interest Cost	7	7	21	21
Defined Benefit Plan Expected Return On Plan Assets	(7)	(7)	(23)	(22)
Defined Benefit Plan Amortization Of Prior Service Cost Credit	(1)	(1)	(2)	(2)
Recognized actuarial loss	3	3	10	8
Defined Benefit Plan, Net Periodic Benefit Cost	5	5	16	13
Other Postretirement Benefit Plans Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan Service Cost	1	0	1	1
Defined Benefit Plan Interest Cost	1	1	4	4
Defined Benefit Plan Expected Return On Plan Assets	(1)	(1)	(4)	(4)
Defined Benefit Plan Amortization Of Prior Service Cost Credit	(1)	(1)	(3)	(3)
Recognized actuarial loss	0	1	1	2
Defined Benefit Plan, Net Periodic Benefit Cost	$ 0	$ 0	$ (1)	$ 0