Financial Information By Business Segments (Financial Information By Business Segments) (Detail) - USD ($) $ in Millions		3 Months Ended				6 Months Ended
		Jun. 30, 2021		Jun. 30, 2020		Jun. 30, 2021		Jun. 30, 2020	Dec. 31, 2020
Segment Reporting Information [Line Items]
Operating Revenues		$ 1,874		$ 2,050		$ 4,763		$ 4,831
Net Income (Loss)		(177)		451		471		899
Property, Plant and Equipment, Additions		670		694		1,303		1,414
Total Assets		49,292				49,292			$ 50,050
Investments in Equity Method Subsidiaries		158				158			64
Public Service Electric and Gas Company [Member]
Segment Reporting Information [Line Items]
Operating Revenues		1,514		1,456		3,587		3,339
PSEG Power [Member]
Segment Reporting Information [Line Items]
Operating Revenues		380		683		1,547		1,903
Other [Member]
Segment Reporting Information [Line Items]
Operating Revenues		155		148		306		304
Operating Segments [Member] | Public Service Electric and Gas Company [Member]
Segment Reporting Information [Line Items]
Operating Revenues		1,514		1,456		3,587		3,339
Net Income (Loss)		309		283		786		723
Property, Plant and Equipment, Additions		633		570		1,219		1,190
Total Assets		36,396				36,396			35,581
Investments in Equity Method Subsidiaries		0				0			0
Operating Segments [Member] | PSEG Power [Member]
Segment Reporting Information [Line Items]
Operating Revenues		380		683		1,547		1,903
Net Income (Loss)		(483)	[1]	170	[1]	(322)	[1]	183
Property, Plant and Equipment, Additions		36		121		82		218
Total Assets		11,031				11,031			12,704
Investments in Equity Method Subsidiaries		67				67			64
Impairment of Long-Lived Assets Held-for-use, net of tax		373				373
non trading commodity mark to market gains (losses), net of tax		(206)		(77)		(240)
Operating Segments [Member] | Other [Member]
Segment Reporting Information [Line Items]
Operating Revenues	[2]	155		148		306		304
Net Income (Loss)	[2]	(3)		(2)		7		(7)
Property, Plant and Equipment, Additions	[2]	1		3		2		6
Total Assets	[2]	2,669				2,669			2,692
Investments in Equity Method Subsidiaries	[2]	91				91			0
Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	[3]	(175)		(237)		(677)		(715)
Net Income (Loss)	[3]	0		0		0		0
Property, Plant and Equipment, Additions	[3]	0		0		0		0
Total Assets	[3]	(804)				(804)			(927)
Investments in Equity Method Subsidiaries	[3]	0				0			0
PSEG Power [Member]
Segment Reporting Information [Line Items]
Operating Revenues		380		683		1,547		1,903
Net Income (Loss)		(483)		$ 170		(322)		$ 183
Total Assets		$ 11,031				$ 11,031			$ 12,704

[1] Includes a $373 million after-tax impairment of the ISO NE asset grouping at PSEG Power in the three and six months ended June 30, 2021. See Note 4. Early Plant Retirements/Asset Dispositions and Impairments for additional information. Also includes net after-tax losses of $(206) million and $(77) million for the three months ended June 30, 2021 and 2020, respectively, and $(240) million for the six months ended June 30, 2021 related to the impacts of non-trading commodity mark-to-market activity, which consist of the financial impact from positions with future delivery dates.

[2] Includes amounts applicable to Energy Holdings and PSEG LI, which are below the quantitative threshold for separate disclosure as reportable segments. Other also includes amounts applicable to PSEG (parent company) and Services.

[3] Intercompany eliminations primarily relate to intercompany transactions between PSE&G and PSEG Power. For a further discussion of the intercompany transactions between PSE&G and PSEG Power, see Note 20. Related-Party Transactions.