Financial Information By Business Segments (Financial Information By Business Segments) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011		Dec. 31, 2011
Segment Reporting Information [Line Items]
Operating Revenues	$ 2,402		$ 2,620		$ 7,375		$ 8,443
Income (Loss) From Continuing Operations	347		265		1,051		1,047
Income (Loss) from Discontinued Operations, net of tax			29				96
Net Income (Loss)	347		294		1,051		1,143
Segment Earnings (Loss)	347		294		1,051		1,143
Gross Additions to Long-Lived Assets	689		477		1,969		1,479
Total Assets	30,706		29,821		30,706		29,821		29,821
Investments in Equity Method Subsidiaries	140		137		140		137
Power [Member]
Segment Reporting Information [Line Items]
Operating Revenues	1,038		1,398		3,584		4,650
Income (Loss) From Continuing Operations	181		273		538		775
Income (Loss) from Discontinued Operations, net of tax			29				96
Net Income (Loss)	181		302		538		871
Segment Earnings (Loss)	181		302		538		871
Gross Additions to Long-Lived Assets	149		207		493		530
Total Assets	10,994		11,087		10,994		11,087
Investments in Equity Method Subsidiaries	41		31		41		31
PSE And G [Member]
Segment Reporting Information [Line Items]
Operating Revenues	1,683		1,841		5,029		5,718
Income (Loss) From Continuing Operations	155		154		453		422
Income (Loss) from Discontinued Operations, net of tax			0				0
Net Income (Loss)	155		154		453		422
Segment Earnings (Loss)	155		154		453		422
Gross Additions to Long-Lived Assets	499		265		1,369		939
Total Assets	18,115		17,487		18,115		17,487
Investments in Equity Method Subsidiaries	0		0		0		0
Energy Holdings [Member]
Segment Reporting Information [Line Items]
Operating Revenues	15		(247)		49		(206)
Income (Loss) From Continuing Operations	7		(166)		49		(164)
Income (Loss) from Discontinued Operations, net of tax			0				0
Net Income (Loss)	7		(166)		49		(164)
Segment Earnings (Loss)	7		(166)		49		(164)
Gross Additions to Long-Lived Assets	30		1		85		2
Total Assets	1,974		1,888		1,974		1,888
Investments in Equity Method Subsidiaries	99		106		99		106
PSEG Other [Member]
Segment Reporting Information [Line Items]
Operating Revenues	(334)	[1]	(372)	[1]	(1,287)	[1]	(1,719)	[1]
Income (Loss) From Continuing Operations	4	[1]	4	[1]	11	[1]	14	[1]
Income (Loss) from Discontinued Operations, net of tax			0	[1]			0	[1]
Net Income (Loss)	4	[1]	4	[1]	11	[1]	14	[1]
Segment Earnings (Loss)	4	[1]	4	[1]	11	[1]	14	[1]
Gross Additions to Long-Lived Assets	11	[1]	4	[1]	22	[1]	8	[1]
Total Assets	(377)	[1]	(641)	[1]	(377)	[1]	(641)	[1]
Investments in Equity Method Subsidiaries	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 0	[1]

[1] Other activities include amounts applicable to PSEG (as parent company), Services and intercompany eliminations, primarily relating to intercompany transactions between Power and PSE&G. No gains or losses are recorded on any intercompany transactions; rather, all intercompany transactions are priced in accordance with applicable regulations, including affiliate pricing rules, or at cost or, in the case of the BGS and BGSS contracts between Power and PSE&G, at rates prescribed by the BPU. For a further discussion of the intercompany transactions between Power and PSE&G, see Note 17. Related-Party Transactions.