Income Taxes (Narrative) (Details) (USD $) In Billions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Income Tax Disclosure [Abstract]
Effective income tax rate	27.00%	28.00%
Undistributed earnings of foreign subsidiaries	$ 2

Amount of undistributed earnings of foreign subsidiaries intended to be permanently reinvested outside the country of domicile.

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