Goodwill and Other Intangible Assets (Summary of Changes in Customer Related Other Intangible Assets) (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Finite-Lived Intangible Assets [Line Items]
Other intangible assets, beginning balance	$ 1,797
Amortization expense	(128.0)	(169.0)
Other intangible assets, ending balance	2,153
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Other intangible assets, beginning balance	726
Amortization expense	(74.0)
Other intangible assets, ending balance	$ 652