Additional Financial Information Depreciation and Amortization (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Property, Plant and Equipment [Line Items]
Total depreciation and amortization	$ 242	$ 104	$ 524	$ 313
Amortization of intangible assets
Property, Plant and Equipment [Line Items]
Total depreciation and amortization	226	87	477	262
Amortization of capitalized software
Property, Plant and Equipment [Line Items]
Total depreciation and amortization	11	13	33	39
Depreciation of fixed assets
Property, Plant and Equipment [Line Items]
Total depreciation and amortization	$ 5	$ 4	$ 14	$ 12