Income Taxes (Unrecognized Tax Benefits) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
PSEG [Member]
Total Amount of Unrecognized Tax Benefits at January	$ 756	$ 836	$ 1,403
Increases as a Result of Positions Taken in a Prior Period	58	290	37
Decreases as a Result of Positions Taken in a Prior Period	(22)	(450)	(580)
Increases as a Result of Positions Taken during the Current Period	37	82	15
Decreases as a Result of Positions Taken during the Current Period	(4)	(2)	(19)
Decreases as a Result of Settlements with Taxing Authorities	0	0	(5)
Decreases due to Lapses of Applicable Statute of Limitations	0	0	(15)
Total Amount of Unrecognized Tax Benefits at December	825	756	836
Accumulated Deferred Income Taxes Associated with Unrecognized Tax Benefits	(379)	(332)	(508)
Regulatory Asset-Unrecognized Tax Benefits	(20)	(16)	(55)
Total Amount of Unrecognized Tax Benefits that if Recognized, would Impact the Effective Tax Rate (including Interest and Penalties)	426	408	273
Power [Member]
Total Amount of Unrecognized Tax Benefits at January	101	(42)	30
Increases as a Result of Positions Taken in a Prior Period	24	111	1
Decreases as a Result of Positions Taken in a Prior Period	(9)	(29)	(39)
Increases as a Result of Positions Taken during the Current Period	8	63	1
Decreases as a Result of Positions Taken during the Current Period	(3)	(2)	(18)
Decreases as a Result of Settlements with Taxing Authorities	0	0	(5)
Decreases due to Lapses of Applicable Statute of Limitations	0	0	(12)
Total Amount of Unrecognized Tax Benefits at December	121	101	(42)
Accumulated Deferred Income Taxes Associated with Unrecognized Tax Benefits	(77)	(67)	37
Regulatory Asset-Unrecognized Tax Benefits	0	0	0
Total Amount of Unrecognized Tax Benefits that if Recognized, would Impact the Effective Tax Rate (including Interest and Penalties)	44	34	(5)
PSE&G [Member]
Total Amount of Unrecognized Tax Benefits at January	82	35	27
Increases as a Result of Positions Taken in a Prior Period	14	79	8
Decreases as a Result of Positions Taken in a Prior Period	0	(38)	(9)
Increases as a Result of Positions Taken during the Current Period	18	6	10
Decreases as a Result of Positions Taken during the Current Period	(1)	0	(1)
Decreases as a Result of Settlements with Taxing Authorities	0	0	0
Decreases due to Lapses of Applicable Statute of Limitations	0	0	0
Total Amount of Unrecognized Tax Benefits at December	113	82	35
Accumulated Deferred Income Taxes Associated with Unrecognized Tax Benefits	(65)	(38)	22
Regulatory Asset-Unrecognized Tax Benefits	(20)	(16)	(55)
Total Amount of Unrecognized Tax Benefits that if Recognized, would Impact the Effective Tax Rate (including Interest and Penalties)	28	28	2
Energy Holdings [Member]
Total Amount of Unrecognized Tax Benefits at January	539	820	1,323
Increases as a Result of Positions Taken in a Prior Period	17	90	26
Decreases as a Result of Positions Taken in a Prior Period	(12)	(383)	(530)
Increases as a Result of Positions Taken during the Current Period	11	12	4
Decreases as a Result of Positions Taken during the Current Period	0	0	0
Decreases as a Result of Settlements with Taxing Authorities	0	0	0
Decreases due to Lapses of Applicable Statute of Limitations	0	0	(3)
Total Amount of Unrecognized Tax Benefits at December	555	539	820
Accumulated Deferred Income Taxes Associated with Unrecognized Tax Benefits	(213)	(204)	(551)
Regulatory Asset-Unrecognized Tax Benefits	0	0	0
Total Amount of Unrecognized Tax Benefits that if Recognized, would Impact the Effective Tax Rate (including Interest and Penalties)	$ 342	$ 335	$ 269