Income Taxes (Narrative) (Detail) (USD $) In Millions, unless otherwise specified	0 Months Ended			6 Months Ended			16 Months Ended		6 Months Ended
	Jun. 26, 2009	Sep. 15, 2008	Dec. 17, 2007	Jun. 30, 2012 Year	Jun. 30, 2012 Power [Member]	Jun. 30, 2012 PSEG [Member] Year	Dec. 31, 2011 PSEG [Member]	Mar. 31, 2012 PSEG [Member]	Jun. 30, 2012 PSE And G [Member]
Component of Other Expense, Nonoperating [Line Items]
Bonus depreciation for tax purposes						50.00%	100.00%
Average tax benefits recognition period				20		10
Investment tax credit									$ 11
Decrease in unrecognized tax benefits reasonably likely to increase or decrease within one year						546	159	546
Tax benefits from IRS settlement in leasing issue						387		387
Impact Of unrecognized tax						228
Interest and penalties for decrease in uncertain tax position						356
Amount of unrecognized tax benefits that would affect the effective tax rate				318
Tax deposit	140	80	100
Unrecognized tax benefit decrease on settlement with IRS					$ 1	$ 70			$ 30