Goodwill and Other Intangible Assets (Intangible Assets Subject to Amortization) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 5,728		$ 5,728		$ 5,772
Accumulated amortization	(4,367)		(4,367)		(4,226)
Net	1,361		1,361		1,546
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	359		359		391
Amortization expense	110	147	344	436
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,204		1,204		1,186
Accumulated amortization	(786)		(786)		(697)
Net	418		418		489
Patents, Licenses And Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	235		235		250
Accumulated amortization	(202)		(202)		(208)
Net	33		33		42
Computer Software, Intangible Asset [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	2,167		2,167		2,048
Accumulated amortization	(1,722)		(1,722)		(1,597)
Net	445		445		451
Leases, Acquired-in-Place [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,315		1,315		1,470
Accumulated amortization	(881)		(881)		(944)
Net	434		434		526
Present Value Of Future Profits [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	524		524		491
Accumulated amortization	(524)		(524)		(491)
Net	0		0		0
All Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	283		283		327
Accumulated amortization	(252)		(252)		(289)
Net	$ 31		$ 31		$ 38