Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Tax Provision [Abstract]
Forecasted tax expense by jurisdiction			$ 109	$ 91
Adjustments to income tax provision [Abstract]
Recognition of certain historical tax benefits as prior uncertainty regarding those benefits has been resolved			0	(1)
Tax effect of goodwill impairment			10	0
Finalization of prior year returns			(4)	9
Tax effects of changes in legislation			0	(7)
Changes in valuation allowances			0	5
Accrual adjustments and other			(1)	0
Tax provision	$ 66	$ 64	$ 114	$ 97
Tax Rate [Abstract]
Forecasted tax expense by jurisdiction (in hundredths)			24.00%	23.80%
Adjustments to income tax provision [Abstract]
Recognition of certain historical tax benefits as prior uncertainty regarding those benefits has been resolved (in hundredths)			0.00%	(0.10%)
Tax effect of goodwill impairment (in hundredths)			2.10%	0.00%
Finalization of prior year returns (in hundredths)			(0.90%)	2.40%
Tax effects of changes in legislation (in hundredths)			0.00%	(1.90%)
Changes in valuation allowances (in hundredths)			0.00%	1.40%
Accrual adjustments and other (in hundredths)			(0.10%)	0.00%
Tax provision (in hundredths)			25.10%	25.60%