Fair Value Measurements (Schedule Of Quantitative Information About Level 3 Fair Value Measurements) (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Assets, Fair Value Disclosure	$ 10
Liabilities, Fair Value Disclosure	(3)
PSEG Power LLC
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Assets, Fair Value Disclosure		$ 7
Liabilities, Fair Value Disclosure		(6)
Electric Load Contracts [Member] \| PSEG Power LLC
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Assets, Fair Value Disclosure	10	2
Liabilities, Fair Value Disclosure	$ 0	$ (5)
Valuation Technique used	Discounted Cash flow	Discounted Cash flow
Fair Value Measurement With Significant Unobservable Inputs	Historic Load Variability	Historic Load Variability
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%	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%	15.00%
Gas Physical Contract [Member] \| PSEG Power LLC
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Assets, Fair Value Disclosure	$ 0	$ 5
Liabilities, Fair Value Disclosure	$ (3)	$ (1)
Valuation Technique used	Discounted Cash flow	Discounted Cash flow
Fair Value Measurement With Significant Unobservable Inputs	Average Historical Basis	Average Historical Basis
Gas Physical Contract [Member] \| PSEG Power LLC \| Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Average Historical Basis	(50.00%)	(40.00%)
Gas Physical Contract [Member] \| PSEG Power LLC \| Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items] (Deprecated 2018-01-31)
Average Historical Basis	0.00%	0.00%

Average Historical Basis

No definition available.

Name:	pseg_AverageHistoricalBasis
Namespace Prefix:	pseg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value, measurement with significant unobservable inputs

+ References

No definition available.

+ Details

Name:	pseg_FairValueMeasurementWithSignificantUnobservableInputs
Namespace Prefix:	pseg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Historic Load Variability

+ References

No definition available.

+ Details

Name:	pseg_HistoricLoadVariability
Namespace Prefix:	pseg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Valuation Technique used

+ References

No definition available.

+ Details

Name:	pseg_ValuationTechniqueused
Namespace Prefix:	pseg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- 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

+ Details

Name:	us-gaap_AssetsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

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.

+ Details

Name:	us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value of financial and nonfinancial obligations.

+ References

+ Details

Name:	us-gaap_LiabilitiesFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	dei_LegalEntityAxis=pseg_PSEGPowerLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=pseg_ElectricLoadDealsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=pseg_GasPhysicalContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: