Financial Information By Business Segments (Financial Information By Business Segments) (Detail) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Operating Revenues		$ 2,302	$ 2,394	$ 7,598	$ 7,228
Net Income		403	412	1,256	1,239
Property, Plant and Equipment, Additions		779	1,023	2,383	3,028
Total Assets		46,815		46,815		$ 45,326
Investments in Equity Method Subsidiaries		67		67		86
Public Service Electric and Gas Company [Member]
Segment Reporting Information [Line Items]
Operating Revenues		1,604	1,595	5,018	4,826
PSEG Power [Member]
Segment Reporting Information [Line Items]
Operating Revenues		771	868	3,270	3,038
Other [Member]
Segment Reporting Information [Line Items]
Operating Revenues		151	151	379	421
Operating Segments [Member] | Public Service Electric and Gas Company [Member]
Segment Reporting Information [Line Items]
Operating Revenues		1,604	1,595	5,018	4,826
Net Income		344	278	974	828
Property, Plant and Equipment, Additions		608	766	1,866	2,213
Total Assets		32,652		32,652		31,109
Investments in Equity Method Subsidiaries		0		0		0
Operating Segments [Member] | PSEG Power [Member]
Segment Reporting Information [Line Items]
Operating Revenues		771	868	3,270	3,038
Net Income		53	125	309	400
Property, Plant and Equipment, Additions		168	253	507	800
Total Assets		12,553		12,553		12,594
Investments in Equity Method Subsidiaries		67		67		86
Operating Segments [Member] | Other [Member]
Segment Reporting Information [Line Items]
Operating Revenues	[1]	151	151	379	421
Net Income	[1]	6	9	(27)	11
Property, Plant and Equipment, Additions	[1]	3	4	10	15
Total Assets	[1]	2,384		2,384		2,604
Investments in Equity Method Subsidiaries	[1]	0		0		0
Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	[2]	(224)	(220)	(1,069)	(1,057)
Net Income	[2]	0	0	0
Property, Plant and Equipment, Additions	[2]	0	0	0	0
Total Assets	[2]	(774)		(774)		(981)
Investments in Equity Method Subsidiaries	[2]	0		0		0
PSEG Power [Member]
Segment Reporting Information [Line Items]
Gain (Loss) on Disposition of Assets, after tax				(286)
Operating Revenues		771	868	3,270	3,038
Net Income		53	$ 125	309	$ 400
Total Assets		$ 12,553		$ 12,553		$ 12,594

[1] 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.

[2] 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.