Goodwill and Other Intangible Assets (Intangible Assets Subject to Amortization) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 4,558		$ 4,715
Accumulated amortization	(3,442)		(3,648)
Net	1,116		1,067
Intangible Assets, Net (Excluding Goodwill)			1,067
Increase (Decrease) in Intangible Assets, Current	157
Amortization expense	153	83
Adjustment To Present Value Of Future Profits In Run Off Insurance Operation	287		293
Computer Software, Intangible Asset [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,674		2,108
Accumulated amortization	1,397		1,609
Net	277		499
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,277		1,345
Accumulated amortization	752		844
Net	525		501
Leases, Acquired-in-Place [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	251		140
Accumulated amortization	(124)		(124)
Net	127		16
Present Value Of Future Profits [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	623		614
Accumulated amortization	623		614
Net	0		0
Patents And Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	85		87
Accumulated amortization	(82)		(83)
Net	3		4
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	39		30
Accumulated amortization	6		20
Net	33		10
All Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	609		391
Accumulated amortization	(458)		(354)
Net	$ 151		$ 37