Common Stock (Earnings Per Share Data)(Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Common Stock [Line Items]
Income (Loss) from Continuing Operations Attributable to Parent	$ 773	$ 746
Average shares, basic	708	706
Average shares, diluted	708	706
EPS, basic (usd per share)	$ 1.09	$ 1.05
EPS, diluted (usd per share)	$ 1.09	$ 1.05
Common Class A [Member]
Common Stock [Line Items]
Income (Loss) from Continuing Operations Attributable to Parent	$ 772	$ 744
Average shares, basic	708	706
Average shares, diluted	708	706
EPS, basic (usd per share)	$ 1.09	$ 1.05
EPS, diluted (usd per share)	$ 1.09	$ 1.05
Number of stock options and performance and unvested stock awards excluded from the dilutive securities calculation	2	2
Dividends declared per share (usd per share)	$ 0.795	$ 0.78

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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Aggregate dividends declared during the period for each share of common stock outstanding.

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Amount of income (loss) from continuing operations attributable to the parent. Also defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests.

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The amount of net income (loss) from continuing operations per each share of common stock or unit outstanding during the reporting period.

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