Financial Instruments (Schedule Of Investment Securities) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Held to maturity
Cost	$ 28	$ 26
Unrealized Gains	0	0
Unrealized Losses	0	0
Securities held to maturity	$ 28	$ 26

Amount of investment in debt security measured at amortized cost (held-to-maturity).

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-Publisher FASB
-Name Accounting Standards Codification
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Amount of accumulated unrecognized gain on investment in debt security measured at amortized cost (held-to-maturity).

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
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Amount of accumulated unrealized loss on investment in debt security measured at amortized cost (held-to-maturity).

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Fair value of investment in debt security measured at amortized cost (held-to-maturity).

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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