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Derivative And Credit-Related Financial Instruments Derivative And Credit-Related Financial Instruments (Schedule of Effects of Fair Value Hedging on the Consolidated Statements of Comprehensive Income) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement [Line Items]
Interest on medium- and long-term debt	[1]	$ 35	$ 80	$ 197
Swaps - fair value - receive fixed/pay floating | Risk management purposes | Interest Rate Swap [Member]
Statement [Line Items]
Interest rate contracts: Hedged items		102	109	110
Interest rate contracts: Derivatives designated as hedging instruments		$ (68)	$ (51)	$ (4)
[1] Includes the effects of hedging.

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- Definition

[Line Items] for Effects of fair value hedging of the derivative instruments used for managing interest rate risk on the Consolidated Statements o Comprehensive Income [Table]

+ References

No definition available.

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- Definition

Interest expense on hedged medium- and long-term debt

+ References

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- Definition

Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=121577467&loc=d3e76258-113986

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- Definition

Aggregate amount of interest paid or due on all long-term debt.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.8)
-URI http://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-K (SK)
-Number 229
-Section 1402
-Paragraph (a)

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-K (SK)
-Number 229
-Section 1402
-Paragraph (b)
-Subparagraph (1)

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