Share-Based Compensation (Narrative) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2020
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	$ 223			$ 223
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Stock Options	58			58
Stock Repurchase Program, Authorized Amount	3,700			3,700
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 1,030			$ 1,030
Dividends Payable, Date Declared	Sep. 10, 2020	May 21, 2020	Mar. 19, 2020
Dividends Payable, Amount Per Share	$ 0.18	$ 0.18	$ 0.18	$ 0.18
Dividends Payable, Date to be Paid	Oct. 13, 2020	Jul. 17, 2020	Apr. 17, 2020
Dividends Payable, Date of Record	Sep. 25, 2020	Jun. 05, 2020	Apr. 03, 2020
Dividends Payable	$ 56			$ 56
Treasury stock purchases				$ 650
Treasury Stock, Shares, Acquired				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 1 month 13 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 11 months 15 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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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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