Discontinued Operations and Dispositions (Operating Results Reclassified To Discontinued Operations) (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
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (Loss) on Discontinued Operations, net of tax	$ 0	$ 0	$ 0	$ 0	$ 0	$ 29	$ 3	$ 64	$ 0	$ 96	$ 7
PSEG Texas [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Operating Revenues										112	402
Income Before Income Taxes										26	15
Income (Loss) on Discontinued Operations, net of tax										$ 17	$ 7