Business Group Information (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Business Group Information [Line Items]
Revenues from international operations	$ 32,677	$ 32,466	$ 31,981
Long-lived assets of operations located outside the United States, percent of total	6.00%	8.00%
Number Of Business Groups	4
International Operations [Member]
Business Group Information [Line Items]
Revenues from international operations	$ 5,700	$ 5,400	$ 5,500