Additional Financial Information Depreciation and Amortization (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Property, Plant and Equipment [Line Items]
Total depreciation and amortization	$ 193	$ 105	$ 282	$ 209
Amortization of intangible assets
Property, Plant and Equipment [Line Items]
Total depreciation and amortization	176	87	251	175
Amortization of capitalized software
Property, Plant and Equipment [Line Items]
Total depreciation and amortization	11	14	22	26
Depreciation of fixed assets
Property, Plant and Equipment [Line Items]
Total depreciation and amortization	$ 6	$ 4	$ 9	$ 8