Goodwill and Other Intangible Assets (Intangible Assets Subject to Amortization) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 5,143	$ 5,131
Accumulated amortization	(3,967)	(3,995)
Net	1,176	1,136
Intangible Assets, Net (Excluding Goodwill)	1,176	1,136
Increase (Decrease) in Intangible Assets, Current	353
Amortization expense	403	425	447
Adjustment To Present Value Of Future Profits In Run Off Insurance Operation	293	322
2015	355
2016	296
2017	225
2018	146
2019	123
Computer Software, Intangible Asset [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	2,148	2,200
Accumulated amortization	(1,638)	(1,707)
Net	510	493
Finite-lived Intangible Assets Acquired	88
Finite-Lived Intangible Assets, Useful Life Average	6 years 8 months 12 days
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,345	1,173
Accumulated amortization	(844)	(802)
Net	501	371
Finite-lived Intangible Assets Acquired	264
Finite-Lived Intangible Assets, Useful Life Average	7 years 7 months 12 days
Leases, Acquired-in-Place [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	485	703
Accumulated amortization	(377)	(498)
Net	108	205
Finite-lived Intangible Assets Acquired	1
Finite-Lived Intangible Assets, Useful Life Average	7 years
Present Value Of Future Profits [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	614	574
Accumulated amortization	(614)	(574)
Net	0	0
Patents And Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	87	106
Accumulated amortization	(83)	(102)
Net	4	4
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	30	49
Accumulated amortization	(20)	(36)
Net	10	13
All Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	434	326
Accumulated amortization	(391)	(276)
Net	$ 43	$ 50
Finite-Lived Intangible Assets, Useful Life Average	1 year