Debt and Credit Facilities (Changes in Long-Term Debt) (Detail) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019
Debt Instrument [Line Items]
Issuance of Long-term Debt	$ 2,450	$ 1,900
Public Service Electric and Gas Company [Member]
Debt Instrument [Line Items]
Issuance of Long-term Debt	1,350	$ 1,150
Medium Term Notes Two Point Four Five Percent due Two Thousand Thirty [Member] \| Public Service Electric and Gas Company [Member]
Debt Instrument [Line Items]
Issuance of Long-term Debt	$ 300
Debt Instrument, Interest Rate, Stated Percentage	2.45%
Medium Term Notes Three Point One Five Percent due Two Thousand Fifty [Member] \| Public Service Electric and Gas Company [Member]
Debt Instrument [Line Items]
Issuance of Long-term Debt	$ 300
Debt Instrument, Interest Rate, Stated Percentage	3.15%
Medium Term Notes Two Point Seven Zero Percent due Two Thousand Fifty [Member] \| Public Service Electric and Gas Company [Member]
Debt Instrument [Line Items]
Issuance of Long-term Debt	$ 375
Debt Instrument, Interest Rate, Stated Percentage	2.70%
Senior Notes Five Point One Three Percentage Due Two Thousand Twenty [Member] \| PSEG Power [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.13%
Repayments of Long-term Debt	$ 406
Senior Notes Zero Point Eight Zero Percent due Two Thousand Twenty Five [Member]
Debt Instrument [Line Items]
Issuance of Long-term Debt	$ 550
Debt Instrument, Interest Rate, Stated Percentage	0.80%
Senior Notes One Point Six Zero Percent due Two Thousand Thirty [Member]
Debt Instrument [Line Items]
Issuance of Long-term Debt	$ 550
Debt Instrument, Interest Rate, Stated Percentage	1.60%
Medium Term Notes Two Point Zero Five Percent due Two Thousand Fifty [Member] \| Public Service Electric and Gas Company [Member]
Debt Instrument [Line Items]
Issuance of Long-term Debt	$ 375
Debt Instrument, Interest Rate, Stated Percentage	2.05%
Medium Term Notes Three Point Five Zero due Two Thousand Twenty [Member] \| Public Service Electric and Gas Company [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.50%
Repayments of Long-term Debt	$ 250

Contractual interest rate for funds borrowed, under the debt agreement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3255-108585

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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