Financial Information By Business Segments (Financial Information By Business Segments) (Detail) - USD ($) $ in Millions		3 Months Ended				9 Months Ended
		Sep. 30, 2021		Sep. 30, 2020		Sep. 30, 2021		Sep. 30, 2020		Dec. 31, 2020
Segment Reporting Information [Line Items]
Operating Revenues		$ 1,903		$ 2,370		$ 6,666		$ 7,201
Net Income (Loss)		(1,564)	[1]	575	[2]	(1,093)	[1]	1,474	[2]
Property, Plant and Equipment, Additions		743		678		2,046		2,092
Total Assets		49,426				49,426				$ 50,050
Investments in Equity Method Subsidiaries		162				162				64
Public Service Electric and Gas Company [Member]
Segment Reporting Information [Line Items]
Operating Revenues		1,820		1,660		5,407		4,999
PSEG Power [Member]
Segment Reporting Information [Line Items]
Operating Revenues		51		746		1,598		2,649
Gain (loss) on sale, net of tax								86
Other [Member]
Segment Reporting Information [Line Items]
Operating Revenues		159		143		465		447
Operating Segments [Member] | Public Service Electric and Gas Company [Member]
Segment Reporting Information [Line Items]
Operating Revenues		1,820		1,660		5,407		4,999
Net Income (Loss)		389		313		1,175		1,036
Property, Plant and Equipment, Additions		599		587		1,818		1,777
Total Assets		37,179				37,179				35,581
Investments in Equity Method Subsidiaries		0				0				0
Operating Segments [Member] | PSEG Power [Member]
Segment Reporting Information [Line Items]
Operating Revenues		51		746		1,598		2,649
Net Income (Loss)		(1,933)	[1]	254	[2]	(2,255)	[1]	437	[2]
Property, Plant and Equipment, Additions		140		89		222		307
Total Assets		8,950				8,950				12,704
Investments in Equity Method Subsidiaries		64				64				64
Impairment of Long-Lived Assets Held-for-use, net of tax		1,563				1,936
non trading commodity mark to market gains (losses), net of tax		(478)				(718)
Operating Segments [Member] | Other [Member]
Segment Reporting Information [Line Items]
Operating Revenues	[3]	159		143		465		447
Net Income (Loss)	[3]	(20)		8		(13)		1
Property, Plant and Equipment, Additions	[3]	4		2		6		8
Total Assets	[3]	4,558				4,558				2,692
Investments in Equity Method Subsidiaries	[3]	98				98				0
Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	[4]	(127)		(179)		(804)		(894)
Net Income (Loss)	[4]	0		0		0		0
Property, Plant and Equipment, Additions	[4]	0		0		0		0
Total Assets	[4]	(1,261)				(1,261)				(927)
Investments in Equity Method Subsidiaries	[4]	0				0				0
PSEG Power [Member]
Segment Reporting Information [Line Items]
Operating Revenues		51		746		1,598		2,649
Net Income (Loss)		(1,933)		$ 254		(2,255)		$ 437
Total Assets		$ 8,950				$ 8,950				$ 12,704

[1] Includes after-tax impairment losses and other charges related to the pending sale of the Fossil generating assets at PSEG Power of $1,563 million and $1,936 million for the three and nine months ended September 30, 2021, respectively. See Note 4. Early Plant Retirements/Asset Dispositions and Impairments for additional information. Also includes net after-tax losses of $478 million and $718 million for the three and nine months ended September 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 an after-tax gain of $86 million in the three and nine months ended September 30, 2020 related to the sale of PSEG Power’s interest in the Yards Creek generation facility. See Note 4. Early Plant Retirements/Asset Dispositions and Impairments

[3] 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.

[4] 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.