Intangible Assets (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Non-Amortizable Assets:
Goodwill, Beginning Balance	$ 986	$ 986
Goodwill, Additions
Goodwill, Ending Balance	986	986
Trademarks and tradenames, Beginning Balance	314
Trademarks and tradenames, Ending Balance	314	314
Other Intangible Assets:
Total Other Intangible Assets, Beginning balance	1,129	1,130
Total Other Intangible Assets, Additions
Total Other Intangible Assets, Impairment Charge		(1)
Total Other Intangible Assets, Ending balance	1,129	1,129
Accumulated amortization, Beginning Balance	(448)	(360)
Accumulated amortization, Additions	(82)	(88)
Accumulated amortization, Ending Balance	(530)	(448)
Other intangible assets, net, Beginning Balance	681	770
Other intangible assets, net, Additions	(82)	(88)
Other intangible assets, net, Impairment Charge		(1)
Other intangible assets, net, Ending Balance	599	681
Customer Relationships [Member]
Other Intangible Assets:
Total Other Intangible Assets, Beginning balance	1,124	1,125
Total Other Intangible Assets, Additions
Total Other Intangible Assets, Impairment Charge		(1)
Total Other Intangible Assets, Ending balance	1,124	1,124
Accumulated amortization, Beginning Balance	(447)
Accumulated amortization, Ending Balance	(528)	(447)
Vendor Relationships and Other [Member]
Other Intangible Assets:
Total Other Intangible Assets, Beginning balance	5	5
Total Other Intangible Assets, Additions
Total Other Intangible Assets, Ending balance	5	5
Accumulated amortization, Beginning Balance	(1)
Accumulated amortization, Ending Balance	(2)	(1)
Trademarks and Tradenames [Member]
Non-Amortizable Assets:
Trademarks and tradenames, Beginning Balance	314	314
Trademarks and tradenames, Additions
Trademarks and tradenames, Ending Balance	$ 314	$ 314