Income Taxes (Schedule of Income Tax Provision (Benefit)) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Current
US	$ 24	$ 62	$ 11
International	32	35	148
Total	56	97	159
Deferred
US	89	16	(404)
International	4	(1)	2
Total	93	15	(402)
Income tax provision (benefit)	$ 149	$ 112	$ (243)