Financial Information By Business Segment (Financial Information By Business Segment) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Segment Reporting Information [Line Items]
Depreciation and Amortization									$ 976	$ 955	$ 819
Operating Income (Loss)	709	556	621	856	589	971	431	946	2,742	2,937	3,116
Income from Equity Method Investments									4	4	17
Interest Expense									475	472	521
Income Tax Expense (Benefit)									977	1,059	1,042
Net Income (Loss)	360	294	323	526	282	567	224	491	1,503	1,564	1,592
Total Assets	29,821				29,909				29,821	29,909
Power [Member]
Segment Reporting Information [Line Items]
Operating Revenues									6,143	6,558	6,772
Depreciation and Amortization									224	175	184
Operating Income (Loss)									1,771	1,963	2,081
Income from Equity Method Investments									0	0	0
Interest Income									4	3	6
Interest Expense									175	157	161
Income (Loss) before Income Taxes									1,687	1,914	1,958
Income Tax Expense (Benefit)									685	778	767
Income (Loss) from Continuing Operations									1,002	1,136	1,191
Income (Loss) from Discontinued Operations, net of tax									96	7	(2)
Net Income (Loss)									1,098	1,143	1,189
Segment Earnings (Loss)									1,098	1,143	1,189
Gross Additions to Long-Lived Assets									757	825	869
Total Assets	11,087				11,452				11,087	11,452
Investments in Equity Method Subsidiaries	31				25				31	25
PSE&G [Member]
Segment Reporting Information [Line Items]
Operating Revenues									7,326	7,869	8,243
Depreciation and Amortization									719	750	608
Operating Income (Loss)									1,151	886	858
Income from Equity Method Investments									0	0	0
Interest Income									12	7	2
Interest Expense									310	318	312
Income (Loss) before Income Taxes									861	591	551
Income Tax Expense (Benefit)									340	232	226
Income (Loss) from Continuing Operations									521	359	325
Income (Loss) from Discontinued Operations, net of tax									0	0	0
Net Income (Loss)									521	359	325
Segment Earnings (Loss)									521	358	321
Gross Additions to Long-Lived Assets									1,302	1,257	855
Total Assets	17,487				16,873				17,487	16,873
Investments in Equity Method Subsidiaries	0				0				0	0
Energy Holdings [Member]
Segment Reporting Information [Line Items]
Operating Revenues									(140)	137	221
Depreciation and Amortization									15	14	11
Operating Income (Loss)									(197)	81	163
Income from Equity Method Investments									4	4	17
Interest Income									2	2	5
Interest Expense									3	11	37
Income (Loss) before Income Taxes									(193)	86	117
Income Tax Expense (Benefit)									(59)	37	45
Income (Loss) from Continuing Operations									(134)	49	72
Income (Loss) from Discontinued Operations, net of tax									0	0	0
Net Income (Loss)									(134)	49	72
Segment Earnings (Loss)									(134)	49	72
Gross Additions to Long-Lived Assets									4	63	62
Total Assets	1,888				2,234				1,888	2,234
Investments in Equity Method Subsidiaries	106				105				106	105
PSEG Other [Member]
Segment Reporting Information [Line Items]
Operating Revenues									(2,250)	(2,771)	(3,201)
Depreciation and Amortization									18	16	16
Operating Income (Loss)									17	7	14
Income from Equity Method Investments									0	0	0
Interest Income									1	8	(6)
Interest Expense									(13)	(14)	11
Income (Loss) before Income Taxes									29	25	10
Income Tax Expense (Benefit)									11	12	4
Income (Loss) from Continuing Operations									18	13	6
Income (Loss) from Discontinued Operations, net of tax									0	0	0
Net Income (Loss)									18	13	6
Segment Earnings (Loss)									18	14	10
Gross Additions to Long-Lived Assets									20	15	8
Total Assets	(641)				(650)				(641)	(650)
Investments in Equity Method Subsidiaries	0				0				0	0
Consolidated [Member]
Segment Reporting Information [Line Items]
Operating Revenues									11,079	11,793	12,035
Depreciation and Amortization									976	955	819
Operating Income (Loss)									2,742	2,937	3,116
Income from Equity Method Investments									4	4	17
Interest Income									19	20	7
Interest Expense									475	472	521
Income (Loss) before Income Taxes									2,384	2,616	2,636
Income Tax Expense (Benefit)									977	1,059	1,042
Income (Loss) from Continuing Operations									1,407	1,557	1,594
Income (Loss) from Discontinued Operations, net of tax									96	7	(2)
Net Income (Loss)									1,503	1,564	1,592
Segment Earnings (Loss)									1,503	1,564	1,592
Gross Additions to Long-Lived Assets									2,083	2,160	1,794
Total Assets	29,821				29,909				29,821	29,909
Investments in Equity Method Subsidiaries	137				130				137	130
PSEG [Member]
Segment Reporting Information [Line Items]
Income Tax Expense (Benefit)									977	1,059	1,042
Net Income (Loss)									$ 1,503	$ 1,564	$ 1,592