Summary Of Significant Accounting Policies (Intangible Assets) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 3,315	$ 3,199
Accumulated Amortization	1,434	1,320
Net Book Value	1,881	1,879
Customer Related Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,699	1,639
Accumulated Amortization	440	343
Net Book Value	1,259	1,296
Acquired Software And Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	420	339
Accumulated Amortization	204	152
Net Book Value	216	187
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	114	114
Accumulated Amortization	20	14
Net Book Value	94	100
Capitalized Software Development Costs [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	720	730
Accumulated Amortization	477	512
Net Book Value	243	218
Purchased Software [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	362	377
Accumulated Amortization	293	299
Net Book Value	$ 69	$ 78