Stock-based Compensation (Schedule Of Stock-Based Compensation) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock-Based Compensation, Before Tax: [Abstract]
Stock options	$ 16	$ 17	$ 19
Retention awards	77	79	84
Total stock-based compensation, before tax	93	96	103
Excess tax benefits from equity compensation plans, operating activities	$ 52	$ 28	$ 44

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- Definition

Amount of cash outflow for realized tax benefit related to deductible compensation cost reported on the entity's tax return for equity instruments in excess of the compensation cost for those instruments recognized for financial reporting purposes.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 20
-Section 55
-Paragraph 24
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Amount of noncash expense for award of restricted stock or unit under share-based payment arrangement.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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-Section 45
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Amount of noncash expense for share-based payment arrangement.

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-Name Accounting Standards Codification
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Amount of noncash expense for option under share-based payment arrangement.

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