Segment and Geographic Information (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule of revenue and long-lived assets by geographic region
Revenue	$ 1,226	$ 1,116	$ 1,072	$ 1,035	$ 1,004	$ 971	$ 1,020	$ 959	$ 4,450	$ 3,954	$ 3,639
Long-lived Assets	2,944				1,957				2,944	1,957
United States [Member]
Schedule of revenue and long-lived assets by geographic region
Revenue									2,684	2,373	2,253
Long-lived Assets	2,376				873				2,376	873
European region [Member]
Schedule of revenue and long-lived assets by geographic region
Revenue									1,067	951	839
Long-lived Assets	441				638				441	638
Asia [Member]
Schedule of revenue and long-lived assets by geographic region
Revenue									454	423	357
Long-lived Assets	70				406				70	406
Rest of the world [Member]
Schedule of revenue and long-lived assets by geographic region
Revenue									245	207	190
Long-lived Assets	$ 57				$ 40				$ 57	$ 40