Fair Value Measurements (Schedule Of Quantitative Information About Level 3 Fair Value Measurements) (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Assets, Fair Value Disclosure	$ 12	$ 10
Liabilities, Fair Value Disclosure	(5)	(3)
PSEG Power LLC
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Assets, Fair Value Disclosure	12	10
Liabilities, Fair Value Disclosure	(5)	(3)
Electric Load Contracts [Member] \| PSEG Power LLC
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Assets, Fair Value Disclosure	12	10
Liabilities, Fair Value Disclosure	$ 0	$ 0
Valuation Technique used	Discounted Cash flow	Discounted Cash flow
Fair Value Measurement With Significant Unobservable Inputs	Load Shaping Cost	Historic Load Variability
Historic Load Variability	4.00%
Electric Load Contracts [Member] \| PSEG Power LLC \| Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Historic Load Variability		0.00%
Load Shaping Cost	0.00%
Electric Load Contracts [Member] \| PSEG Power LLC \| Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Historic Load Variability		10.00%
Load Shaping Cost	11.00%
Gas Physical Contract [Member] \| PSEG Power LLC
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Assets, Fair Value Disclosure	$ 0	$ 0
Liabilities, Fair Value Disclosure	$ (2)	$ (3)
Valuation Technique used	Discounted Cash flow	Discounted Cash flow
Fair Value Measurement With Significant Unobservable Inputs	Historical Basis Adjustment	Average Historical Basis
Average Historical Basis	(43.00%)
Gas Physical Contract [Member] \| PSEG Power LLC \| Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Average Historical Basis	(60.00%)	50.00%
Gas Physical Contract [Member] \| PSEG Power LLC \| Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Average Historical Basis	(30.00%)
Other (Futures Contracts) [Member] \| PSEG Power LLC
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Assets, Fair Value Disclosure	$ 0
Liabilities, Fair Value Disclosure	$ (3)

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- Definition

Fair value, measurement with significant unobservable inputs

+ References

No definition available.

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- Definition

Historic Load Variability

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Load Shaping Cost

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- Definition

Valuation Technique used

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- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Fair value of financial and nonfinancial obligations.

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