Financial Information By Business Segments (Financial Information By Business Segments) (Detail) - USD ($) $ in Millions		3 Months Ended			9 Months Ended
		Sep. 30, 2020		Sep. 30, 2019	Sep. 30, 2020		Sep. 30, 2019		Dec. 31, 2019
Segment Reporting Information [Line Items]
Operating Revenues		$ 2,370		$ 2,302	$ 7,201		$ 7,598
Net Income (Loss)		575	[1]	403	1,474	[1]	1,256	[1]
Property, Plant and Equipment, Additions		678		779	2,092		2,383
Total Assets		49,576			49,576				$ 47,730
Investments in Equity Method Subsidiaries		67			67				67
Public Service Electric and Gas Company [Member]
Segment Reporting Information [Line Items]
Operating Revenues		1,660		1,604	4,999		5,018
PSEG Power [Member]
Segment Reporting Information [Line Items]
Operating Revenues		746		771	2,649		3,270
Gain (Loss) on disposition of Assets, net of tax		86			86		(286)
Other [Member]
Segment Reporting Information [Line Items]
Operating Revenues		143		151	447		379
Operating Segments [Member] | Public Service Electric and Gas Company [Member]
Segment Reporting Information [Line Items]
Operating Revenues		1,660		1,604	4,999		5,018
Net Income (Loss)		313		344	1,036		974
Property, Plant and Equipment, Additions		587		608	1,777		1,866
Total Assets		34,833			34,833				33,266
Investments in Equity Method Subsidiaries		0			0				0
Operating Segments [Member] | PSEG Power [Member]
Segment Reporting Information [Line Items]
Operating Revenues		746		771	2,649		3,270
Net Income (Loss)		254	[1]	53	437	[1]	309	[1]
Property, Plant and Equipment, Additions		89		168	307		507
Total Assets		12,719			12,719				12,805
Investments in Equity Method Subsidiaries		66			66				66
Operating Segments [Member] | Other [Member]
Segment Reporting Information [Line Items]
Operating Revenues	[2]	143		151	447		379
Net Income (Loss)	[2]	8		6	1		(27)
Property, Plant and Equipment, Additions	[2]	2		3	8		10
Total Assets	[2]	2,952			2,952				2,715
Investments in Equity Method Subsidiaries	[2]	1			1				1
Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	[3]	(179)		(224)	(894)		(1,069)
Net Income (Loss)	[3]	0		0	0
Property, Plant and Equipment, Additions	[3]	0		0	0		0
Total Assets	[3]	(928)			(928)				(1,056)
Investments in Equity Method Subsidiaries	[3]	0			0				0
PSEG Power [Member]
Segment Reporting Information [Line Items]
Operating Revenues		746		771	2,649		3,270
Net Income (Loss)		254		$ 53	437		$ 309
Total Assets		$ 12,719			$ 12,719				$ 12,805

[1] Includes an after-tax gain of $86 million in the three months and nine months ended September 30, 2020 related to the sale of PSEG Power’s interest in the Yards Creek generation facility and an after-tax loss of $286 million in the nine months ended September 30, 2019 related to the sale of PSEG Power’s ownership interests in the Keystone and Conemaugh fossil generation plants. See Item 1. Note 4. Early Plant Retirements/Asset Dispositions for additional information.

[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.