Financial Information By Business Segments (Financial Information By Business Segments) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
Depreciation and Amortization									$ 1,054	$ 976	$ 955
Operating Income (Loss)	468	594	433	783	709	556	621	856	2,278	2,742	2,937
Income from Equity Method Investments									12	4	4
Interest Expense									423	475	472
Income Tax Expense (Benefit)									736	977	1,059
Income (Loss) on Discontinued Operations, net of tax	0	0	0	0	0	29	3	64	0	96	7
Net Income (Loss)	224	347	211	493	360	294	323	526	1,275	1,503	1,564
Total Assets	31,725				29,821				31,725	29,821
Power [Member]
Segment Reporting Information [Line Items]
Operating Revenues									4,865	6,143	6,558
Depreciation and Amortization									237	224	175
Operating Income (Loss)									1,123	1,771	1,963
Income from Equity Method Investments									0	0	0
Interest Income									3	4	3
Interest Expense									134	175	157
Income (Loss) before Income Taxes									1,080	1,687	1,914
Income Tax Expense (Benefit)									433	685	778
Income (Loss) From Continuing Operations									647	1,002	1,136
Income (Loss) on Discontinued Operations, net of tax										96	7
Net Income (Loss)										1,098
Segment Earnings (Loss)									647
Gross Additions to Long-Lived Assets									646	757	825
Total Assets	11,032				11,087				11,032	11,087	11,452
Investments in Equity Method Subsidiaries	40				31				40	31
PSE&G [Member]
Segment Reporting Information [Line Items]
Operating Revenues									6,626	7,326	7,869
Depreciation and Amortization									778	719	750
Operating Income (Loss)									1,083	1,151	886
Income from Equity Method Investments									0	0	0
Interest Income									20	12	7
Interest Expense									295	310	318
Income (Loss) before Income Taxes									835	861	591
Income Tax Expense (Benefit)									307	340	232
Income (Loss) From Continuing Operations									528	521	359
Income (Loss) on Discontinued Operations, net of tax										0	0
Net Income (Loss)									528	521	359
Segment Earnings (Loss)									528	521	358
Gross Additions to Long-Lived Assets									1,770	1,302	1,257
Total Assets	19,223				17,487				19,223	17,487	16,873
Investments in Equity Method Subsidiaries	0				0				0	0	0
Energy Holdings [Member]
Segment Reporting Information [Line Items]
Operating Revenues									113	(140)	137
Depreciation and Amortization									19	15	14
Operating Income (Loss)									62	(197)	81
Income from Equity Method Investments									12	4	4
Interest Income									2	2	2
Interest Expense									1	3	11
Income (Loss) before Income Taxes									78	(193)	86
Income Tax Expense (Benefit)									(8)	(59)	37
Income (Loss) From Continuing Operations									86	(134)	49
Income (Loss) on Discontinued Operations, net of tax										0	0
Net Income (Loss)									86	(134)	49
Segment Earnings (Loss)									86	(134)	49
Gross Additions to Long-Lived Assets									127	4	63
Total Assets	1,454				1,888				1,454	1,888	2,234
Investments in Equity Method Subsidiaries	94				106				94	106	105
PSEG Other [Member]
Segment Reporting Information [Line Items]
Operating Revenues									(1,823)	(2,250)	(2,771)
Depreciation and Amortization									20	18	16
Operating Income (Loss)									10	17	7
Income from Equity Method Investments									0	0	0
Interest Income									2	1	8
Interest Expense									(7)	(13)	(14)
Income (Loss) before Income Taxes									18	29	25
Income Tax Expense (Benefit)									4	11	12
Income (Loss) From Continuing Operations									14	18	13
Income (Loss) on Discontinued Operations, net of tax										0	0
Net Income (Loss)									14	18	13
Segment Earnings (Loss)									14	18	14
Gross Additions to Long-Lived Assets									31	20	15
Total Assets	16				(641)				16	(641)	(650)
Investments in Equity Method Subsidiaries	0				0				0	0	0
Consolidated [Member]
Segment Reporting Information [Line Items]
Operating Revenues									9,781	11,079	11,793
Depreciation and Amortization									1,054	976	955
Operating Income (Loss)									2,278	2,742	2,937
Income from Equity Method Investments									12	4	4
Interest Income									27	19	20
Interest Expense									423	475	472
Income (Loss) before Income Taxes									2,011	2,384	2,616
Income Tax Expense (Benefit)									736	977	1,059
Income (Loss) From Continuing Operations									1,275	1,407	1,557
Income (Loss) on Discontinued Operations, net of tax										96	7
Net Income (Loss)									1,275	1,503	1,564
Segment Earnings (Loss)									1,275	1,503	1,564
Gross Additions to Long-Lived Assets									2,574	2,083	2,160
Total Assets	31,725				29,821				31,725	29,821	29,909
Investments in Equity Method Subsidiaries	134				137				134	137	130
Retained Earnings [Member]
Segment Reporting Information [Line Items]
Net Income (Loss)									1,275	1,503	1,564
Retained Earnings [Member] | Power [Member]
Segment Reporting Information [Line Items]
Net Income (Loss)									647		1,143
Segment Earnings (Loss)										$ 1,098	$ 1,143