Stockholders' Equity (Schedule of Treasury Stock) (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended	161 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021
Class of Stock [Line Items]
Shares repurchased	3,394,548	1,709,431	66,162,599
Average purchase price per share	$ 147.30	$ 87.87	$ 80.15
Shares repurchased (in $ millions)	$ 500	$ 150	$ 5,303
Aggregate Board of Directors repurchase authorizations (in $ millions)	$ 0	$ 0	$ 5,866

Amount of stock repurchase plan authorized in the period.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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- Definition

Total cost of shares repurchased divided by the total number of shares repurchased.

+ References

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-Name Accounting Standards Codification
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-SubTopic 30
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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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