Financial Information By Business Segments (Financial Information By Business Segments) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011		Dec. 31, 2011
Segment Reporting Information [Line Items]
Operating Revenues	$ 2,098		$ 2,469		$ 4,973		$ 5,823
Income (Loss) From Continuing Operations	211		320		704		782
Income (Loss) from Discontinued Operations, net of tax			3				67
Net Income (Loss)	211		323		704		849
Segment Earnings (Loss)	211		323		704		849
Gross Additions to Long-Lived Assets	593		505		1,280		1,002
Total Assets	30,142		29,821		30,142		29,821		29,821
Investments in Equity Method Subsidiaries	144		137		144		137
Power [Member]
Segment Reporting Information [Line Items]
Operating Revenues	985		1,285		2,546		3,252
Income (Loss) From Continuing Operations	104		205		357		502
Income (Loss) from Discontinued Operations, net of tax			3				67
Net Income (Loss)	104		208		357		569
Segment Earnings (Loss)	104		208		357		569
Gross Additions to Long-Lived Assets	107		168		344		323
Total Assets	10,749		11,087		10,749		11,087
Investments in Equity Method Subsidiaries	41		31		41		31
PSE And G [Member]
Segment Reporting Information [Line Items]
Operating Revenues	1,407		1,571		3,346		3,877
Income (Loss) From Continuing Operations	101		105		298		268
Income (Loss) from Discontinued Operations, net of tax			0				0
Net Income (Loss)	101		105		298		268
Segment Earnings (Loss)	101		105		298		268
Gross Additions to Long-Lived Assets	435		335		870		674
Total Assets	17,863		17,487		17,863		17,487
Investments in Equity Method Subsidiaries	0		0		0		0
Energy Holdings [Member]
Segment Reporting Information [Line Items]
Operating Revenues	14		21		34		41
Income (Loss) From Continuing Operations	2		5		42		2
Income (Loss) from Discontinued Operations, net of tax			0				0
Net Income (Loss)	2		5		42		2
Segment Earnings (Loss)	2		5		42		2
Gross Additions to Long-Lived Assets	44		0		55		1
Total Assets	1,953		1,888		1,953		1,888
Investments in Equity Method Subsidiaries	103		106		103		106
PSEG Other [Member]
Segment Reporting Information [Line Items]
Operating Revenues	(308)	[1]	(408)	[1]	(953)	[1]	(1,347)	[1]
Income (Loss) From Continuing Operations	4	[1]	5	[1]	7	[1]	10	[1]
Income (Loss) from Discontinued Operations, net of tax			0	[1]			0	[1]
Net Income (Loss)	4	[1]	5	[1]	7	[1]	10	[1]
Segment Earnings (Loss)	4	[1]	5	[1]	7	[1]	10	[1]
Gross Additions to Long-Lived Assets	7	[1]	2	[1]	11	[1]	4	[1]
Total Assets	(423)	[1]	(641)	[1]	(423)	[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.