Goodwill and Other Intangible Assets - Changes During Period (Details 2) (USD $) In Millions	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Changes in the carrying amount of goodwill [Abstract]
Balance at beginning of period	$ 48,882	$ 48,320	$ 48,854	$ 48,357
Changes during the period:
Business combinations	60	381	66	400
Dispositions	(645)	0	(645)	(19)
Other	(117)	35	(95)	(2)
Balance at March 31,	$ 48,180	$ 48,736	$ 48,180	$ 48,736

Carrying amount as of the balance sheet date, which is the cumulative amount paid and (if applicable) the fair value of any noncontrolling interest in the acquiree, adjusted for any amortization recognized prior to the adoption of any changes in generally accepted accounting principles (as applicable) and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions.

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