Goodwill and Other Intangible Assets (Intangible Assets Subject to Amortization) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 5,249		$ 5,249		$ 5,520
Accumulated amortization	(4,046)		(4,046)		(4,226)
Net	1,203		1,203		1,294
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	336		336		353
Amortization expense	111	124	219	234
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,199		1,199		1,227
Accumulated amortization	(809)		(809)		(808)
Net	390		390		419
Patents, Licenses And Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	195		195		191
Accumulated amortization	(166)		(166)		(160)
Net	29		29		31
Computer Software, Intangible Asset [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	2,246		2,246		2,126
Accumulated amortization	(1,747)		(1,747)		(1,681)
Net	499		499		445
Leases, Acquired-in-Place [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	764		764		1,163
Accumulated amortization	(522)		(522)		(792)
Net	242		242		371
Present Value Of Future Profits [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	553		553		530
Accumulated amortization	(553)		(553)		(530)
Net	0		0		0
All Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	292		292		283
Accumulated amortization	(249)		(249)		(255)
Net	$ 43		$ 43		$ 28