Employee Benefit Plans Employee Benefit Plans (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1	$ 1
Interest cost	14	14
Expected return on plan assets	(19)	(19)
Net amortization	8	12
Net periodic benefit cost	4	8
Other Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	2
Interest cost	7	6
Expected return on plan assets	(8)	(7)
Net amortization	1	2
Net periodic benefit cost	$ 1	$ 3