Segment Information (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Geographic segment information based on geographic location
Net revenue	$ 2,002	$ 2,035	$ 1,996
Long-Lived Assets (excluding financial instruments and deferred tax assets)	2,665	2,863	2,981
United States [Member]
Geographic segment information based on geographic location
Net revenue	795	873	855
Long-Lived Assets (excluding financial instruments and deferred tax assets)	1,774	1,749	1,878
United Kingdom [Member]
Geographic segment information based on geographic location
Net revenue	155	152	141
Long-Lived Assets (excluding financial instruments and deferred tax assets)	27	37	61
All Other Countries [Member]
Geographic segment information based on geographic location
Net revenue	1,052	1,010	1,000
Long-Lived Assets (excluding financial instruments and deferred tax assets)	$ 864	$ 1,077	$ 1,042