Benefit Obligations (Schedule of Net Periodic Benefit Costs Recognized) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3	$ 3
Interest cost	35	42
Expected return on plan assets	(52)	(54)
Amortization of prior service cost (credit), net	0	0
Special termination benefit	1	0
Total	(13)	(9)
Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0
Interest cost	1	2
Expected return on plan assets	0	0
Amortization of prior service cost (credit), net	0	(19)	[1]
Special termination benefit	0	0
Total	$ 1	$ (17)

[1] Primarily related to the elimination of eligibility for all current and future US employees to participate in the Company's US postretirement health care plan.