Share-based Compensation (Unrecognized Compensation Cost) (Details) $ in Millions	9 Months Ended
Sep. 30, 2020 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost	$ 306
PRSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost	$ 3
Weighted-Average Amortization Period (years)	4 months 28 days
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost	$ 228
Weighted-Average Amortization Period (years)	2 years 10 months 24 days
RSUs \| Cash Settlement [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost	$ 62
Weighted-Average Amortization Period (years)	3 years 1 month 9 days
RSUs \| Stock Settlement [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-Average Amortization Period (years)	1 year 5 months 8 days
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost	$ 74
Weighted-Average Amortization Period (years)	2 years 29 days
SARs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost	$ 1
Weighted-Average Amortization Period (years)	11 months 19 days

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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- Definition

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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- 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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