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Income Taxes (Reconciliation Of Changes In Unrecognized Tax Benefits Liabilities/(Assets)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation Of Changes In Unrecognized Tax Benefits Liabilities/(Assets) [Abstract]
Unrecognized tax benefits at January 1	$ 64	$ 174	$ 179
Increases for positions taken in current year	18	20	30
Increases for positions taken in prior years	7	44	9
Decreases for positions taken in prior years	(19)	(96)	(30)
Refunds from and settlements with taxing authorities			21
Payments to and settlements with taxing authorities		(11)
Increases/(decreases) for interest and penalties	5	(5)	4
Lapse of statutes of limitations	(1)	(62)	(39)
Unrecognized tax benefits at December 31	$ 74	$ 64	$ 174

X

- Definition

The net amount of increases and decreases in unrecognized tax benefits for interest and penalties.

+ References

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

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- Definition

Amount of unrecognized tax benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
-Paragraph 10B
-URI http://asc.fasb.org/extlink&oid=120406818&loc=SL37586934-109318

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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

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- Definition

Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

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Amount of increase in unrecognized tax benefits resulting from settlements with taxing authorities.

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

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