Employee Benefit Plans Employee Benefit Plans (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Domestic Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2	$ 2	$ 6	$ 7
Interest cost	15	16	45	48
Expected return on plan assets	(19)	(19)	(56)	(56)
Net amortization	9	6	26	15
Net periodic benefit cost	7	5	21	14
Domestic Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2	2	5	5
Interest cost	7	7	21	23
Expected return on plan assets	(7)	(8)	(22)	(23)
Net amortization	1	5	3	14
Net periodic benefit cost	$ 3	$ 6	$ 7	$ 19