Property, Equipment and Capitalized Software Property, Equipment and Capitalized Software table (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment [Line Items]
Land and improvements	$ 45	$ 38
Buildings and improvements	1,052	764
Computer equipment	1,345	1,418
Furniture and fixtures	274	224
Less accumulated depreciation	(1,424)	(1,417)
Property and equipment, net	1,292	1,027
Capitalized software	2,239	2,535
Less accumulated amortization	(1,016)	(1,362)
Capitalized software, net	1,223	1,173
Total property, equipment and capitalized software, net	$ 2,515	$ 2,200