Segment and Related Information (Geographic Data) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers	$ 12,737	$ 8,521	$ 7,449
Long-Lived Assets	28,125	21,733
US [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers	11,084	7,760	6,733
Long-Lived Assets	19,129	18,228
UK [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues from external customers	1,653	761	716
Long-Lived Assets	$ 8,996	$ 3,505