Goodwill and Other Intangible Assets (Intangible Assets Subject to Amortization) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 26,920		$ 26,061
Accumulated amortization	(12,275)		(11,911)
Net	14,645		14,150
Intangible Assets, Net (Excluding Goodwill)	14,788		14,310
Adjustments To Reflect Present Value Of Future Profits In Run Off Insurance Operations To Reflect Effects That Would Have Been Recognized Had Related Unrealized Investment Securities Holding Gains Loses Actually Been Realized	316		322
Increase (Decrease) in Intangible Assets, Current	859
Amortization expense	420	399
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	8,426		7,938
Accumulated amortization	(2,402)		(2,312)
Net	6,024		5,626
Patents And Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	6,785		6,602
Accumulated amortization	(2,718)		(2,621)
Net	4,067		3,981
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,370		1,356
Accumulated amortization	(312)		(295)
Net	1,058		1,061
Computer Software, Intangible Asset [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	8,478		8,256
Accumulated amortization	(5,420)		(5,252)
Net	3,058		3,004
Leases, Acquired-in-Place [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	679		703
Accumulated amortization	(480)		(498)
Net	199		205
Present Value Of Future Profits [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	583		574
Accumulated amortization	(583)		(574)
Net	0		0
All Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	599		632
Accumulated amortization	(360)		(359)
Net	$ 239		$ 273