Financial Information By Business Segments (Financial Information By Business Segments) (Detail) - USD ($) $ in Millions		3 Months Ended										12 Months Ended
		Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019		Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018		Mar. 31, 2018	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Operating Revenues		$ 2,478	$ 2,302	$ 2,316		$ 2,980	$ 2,468	$ 2,394	$ 2,016		$ 2,818	$ 10,076		$ 9,696	$ 9,094
Depreciation and Amortization												1,248		1,158	1,986
Operating Income (Loss)		507	490	160	[1]	786	501	554	411	[1]	832	1,943		2,298	1,429
Income from Equity Method Investments												14		15	14
Interest Income												26		29	30
Interest Expense												(569)		(476)	(391)
Income (Loss) before Income Taxes												1,950		1,855	1,268
Income Tax Expense (Benefit)												257		417	(306)
Net Income (Loss)												1,693		1,438	1,574
Gross Additions to Long-Lived Assets												3,166		3,912	4,190
Total Assets		47,730					45,326					47,730		45,326	42,716
Investments in Equity Method Subsidiaries		67					86					67		86	87
PSEG Power LLC
Segment Reporting Information [Line Items]
Operating Revenues												4,385		4,146	3,860
Public Service Electric and Gas Company
Segment Reporting Information [Line Items]
Operating Revenues												6,625		6,471	6,324
Other [Member]
Segment Reporting Information [Line Items]
Operating Revenues												549		571	466
Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues												(1,483)		(1,492)	(1,556)
Retained Earnings [Member]
Segment Reporting Information [Line Items]
Net Income (Loss)												1,693		1,438	1,574
Operating Segments [Member] | PSEG Power LLC
Segment Reporting Information [Line Items]
Operating Revenues												4,385		4,146	3,860
Depreciation and Amortization												377		354	1,268
Operating Income (Loss)												448		596	(367)
Income from Equity Method Investments												14		15	14
Interest Income												7		5	3
Interest Expense												(119)		(76)	(50)
Income (Loss) before Income Taxes												671		431	(250)
Income Tax Expense (Benefit)												203		66	(729)
Net Income (Loss)												468	[2]	365	479
Gross Additions to Long-Lived Assets												607		996	1,231
Total Assets		12,805					12,594					12,805		12,594	12,418
Investments in Equity Method Subsidiaries		66					86					66		86	87
Operating Segments [Member] | Public Service Electric and Gas Company
Segment Reporting Information [Line Items]
Operating Revenues												6,625		6,471	6,324
Depreciation and Amortization												837		770	685
Operating Income (Loss)												1,469		1,606	1,760
Income from Equity Method Investments												0		0	0
Interest Income												18		21	24
Interest Expense												(361)		(333)	(303)
Income (Loss) before Income Taxes												1,343		1,411	1,536
Income Tax Expense (Benefit)												93		344	563
Net Income (Loss)												1,250		1,067	973
Gross Additions to Long-Lived Assets												2,542		2,896	2,919
Total Assets		33,266					31,109					33,266		31,109	28,554
Investments in Equity Method Subsidiaries		0					0					0		0	0
Operating Segments [Member] | Other [Member]
Segment Reporting Information [Line Items]
Operating Revenues	[3]											549		571	466
Depreciation and Amortization	[3]											34		34	33
Operating Income (Loss)	[3]											26		96	36
Income from Equity Method Investments	[3]											0		0	0
Interest Income	[3]											6		9	5
Interest Expense	[3]											(94)		(73)	(40)
Income (Loss) before Income Taxes	[3]											(64)		13	(18)
Income Tax Expense (Benefit)	[3]											(39)		7	(140)
Net Income (Loss)	[3]											(25)		6	122
Gross Additions to Long-Lived Assets	[3]											17		20	40
Total Assets	[3]	2,715					2,604					2,715		2,604	2,666
Investments in Equity Method Subsidiaries	[3]	1					0					1		0	0
Eliminations [Member]
Segment Reporting Information [Line Items]
Operating Revenues	[4]											(1,483)		(1,492)	(1,556)
Depreciation and Amortization	[4]											0		0	0
Operating Income (Loss)	[4]											0		0	0
Income from Equity Method Investments	[4]											0		0	0
Interest Income	[4]											(5)		(6)	(2)
Interest Expense	[4]											5		6	2
Income (Loss) before Income Taxes	[4]											0		0	0
Income Tax Expense (Benefit)	[4]											0		0	0
Net Income (Loss)	[4]											0			0
Gross Additions to Long-Lived Assets	[4]											0		0	0
Total Assets	[4]	(1,056)					(981)					(1,056)		(981)	(922)
Investments in Equity Method Subsidiaries	[4]	0					0					0		0	0
PSEG Power LLC
Segment Reporting Information [Line Items]
Gain (Loss) on Disposition of Assets, after tax												(286)
Operating Revenues		1,115	771	1,083		1,416	1,108	868	767		1,403	4,385		4,146	3,860
Depreciation and Amortization												377		354	1,268
Operating Income (Loss)		154	$ 79	$ (86)	[1]	$ 301	113	$ 112	$ 42	[1]	$ 329	448		596	(367)
Income from Equity Method Investments												14		15	14
Interest Expense												(119)		(76)	(50)
Income (Loss) before Income Taxes												671		431	(250)
Income Tax Expense (Benefit)												203		66	(729)
Net Income (Loss)												468		365	479
Total Assets		$ 12,805					$ 12,594					12,805		12,594
PSEG Power LLC | Retained Earnings [Member]
Segment Reporting Information [Line Items]
Net Income (Loss)												$ 468		$ 365	$ 479

[1] The decrease in Operating Income and Net Income at PSEG consolidated and PSEG Power in the second quarter of 2019 as compared to the same quarter in 2018 was primarily due to the loss in 2019 related to the sale of PSEG Power’s ownership interests in the Keystone and Conemaugh fossil generation plants, offsetting MTM net gains in 2019 as compared to net losses in 2018.

[2] Includes an after-tax loss of $286 million related to the sale of PSEG Power’s ownership interests in the Keystone and Conemaugh generation plants. See Note 4. Early Plant Retirements/Asset Dispositions for additional information.

[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 corporation) 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 26. Related-Party Transactions.