Share-Based Compensation (Narrative) (Details) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
Mar. 31, 2020 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Share-based Awards Other than Options	$ 108
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Stock Options	79
Stock Repurchase Program, Authorized Amount	3,700
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 1,030
Dividends Payable, Date Declared	Mar. 19, 2020
Dividends Payable, Amount Per Share \| $ / shares	$ 0.18
Dividends Payable, Date to be Paid	Apr. 17, 2020
Dividends Payable, Date of Record	Apr. 03, 2020
Dividends Payable	$ 55
Treasury Stock, Value, Acquired, Cost Method	$ 650
Treasury Stock, Shares, Acquired \| shares	9,200
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period of recognition for remaining share-based compensation expense	2 years 6 months 7 days
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Period of recognition for remaining share-based compensation expense	1 year 10 months 17 days

Date the declared dividend will be paid, in CCYY-MM-DD format.

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Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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Amount of cost to be recognized for option under share-based payment arrangement.

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Amount of stock repurchase plan authorized.

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Amount remaining of a stock repurchase plan authorized.

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Number of shares that have been repurchased during the period and are being held in treasury.

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Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

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