Asset Impairment, Exit, and Restructuring Costs (Asset Impairment Charges And Exit Costs) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restructuring, Settlement and Impairment Provisions [Abstract]
Restructuring Charges	$ 26	$ 161	$ 29
Equity Method Investment, Other than Temporary Impairment	0	0	12
Goodwill and Intangible Asset Impairment	26	11	9
Other Asset Impairment Charges	28	131	121
Restructuring, Settlement and Impairment Provisions	$ 80	$ 303	$ 171

This item represents an other than temporary decline in value that has been recognized against an investment accounted for under the equity method of accounting. The excess of the carrying amount over the fair value of the investment represents the amount of the write down which is or was reflected in earnings. The written down value is a new cost basis with the adjusted value of the investment becoming its new carrying value subject to the equity accounting method. Evidence of a loss in value might include, but would not necessarily be limited to, absence of an ability to recover the carrying amount of the investment or inability of the investee to sustain an earnings capacity which would justify the carrying amount of the investment.

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-Publisher FASB
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-Section 35
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- Definition

Total loss recognized during the period from the impairment of goodwill plus the loss recognized in the period resulting from the impairment of the carrying amount of intangible assets, other than goodwill.

+ References

No definition available.

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- Definition

The charge against earnings resulting from the write down of long lived assets other than goodwill due to the difference between the carrying value and lower fair value.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
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-Paragraph 2
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-Publisher FASB
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-Topic 230
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-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

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- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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- Definition

Amount of restructuring charges, remediation cost, and asset impairment loss.

+ References

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-Publisher FASB
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