Geographical Information - Long-Lived Assets (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012		Dec. 31, 2011
Long-Lived Assets by Geographical Area
Property and equipment, net	$ 2,289		$ 1,475
United States
Long-Lived Assets by Geographical Area
Property and equipment, net	2,113		1,444
Rest of World
Long-Lived Assets by Geographical Area
Property and equipment, net	$ 176	[1]	$ 31	[1]

[1] No individual country exceeded 10% of our total long-lived assets for any period presented