Employee Benefit Plans (Details) (Other Postretirement Benefit Plans, Defined Benefit [Member], USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 4	$ 3
Expected return on plan assets	(1)	(1)
Amortization of loss	0	1
Amortization of transition obligation	1	1
Net periodic cost	4	4
Expected contribution to postretirement benefit plan in current year	7
Total contribution to the plan during the period	$ 2