For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 42
-URI http://asc.fasb.org/extlink&oid=123359005&loc=d3e9054-108599

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Subparagraph (a)
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Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

Supplementary Financial Information (Narrative) (Details) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2022 USD ($) customer	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($) customer
Supplemental Financial Information [Line Items]
Aggregate amortization expenses	$ 19	$ 17
Goodwill	$ 4,740		$ 4,740
Trade Accounts Receivable [Member]
Supplemental Financial Information [Line Items]
Number of largest customers \| customer	2		2
Customers [Member] \| Trade Accounts Receivable [Member] \| Nonaffiliated REP [Member]
Supplemental Financial Information [Line Items]
Concentration risk percentage	24.00%		22.00%
Customers [Member] \| Trade Accounts Receivable [Member] \| Second Nonaffiliated REP [Member]
Supplemental Financial Information [Line Items]
Concentration risk percentage	23.00%		21.00%