Income Taxes (Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Total Amount of Unrecognized Tax Benefits at January	$ 328	$ 386	$ 332
Increases as a Result of Positions Taken in a Prior Period	40	12	87
Decreases as a Result of Positions Taken in a Prior Period	(32)	(62)	(50)
Increases as a Result of Positions Taken during the Current Period	12	19	28
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	(10)
Decreases due to Lapses of Applicable Statute of Limitations	(13)	(27)	0
Total Amount of Unrecognized Tax Benefits at December	334	328	386
Accumulated Deferred Income Taxes Associated with Unrecognized Tax Benefits	(157)	(200)	(264)
Regulatory Asset-Unrecognized Tax Benefits	(56)	(31)	(27)
Amount of unrecognized tax benefits that would affect the effective tax rate	121	97	95
Power [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Total Amount of Unrecognized Tax Benefits at January	128	111	70
Increases as a Result of Positions Taken in a Prior Period	18	6	28
Decreases as a Result of Positions Taken in a Prior Period	(10)	(1)	(6)
Increases as a Result of Positions Taken during the Current Period	6	12	23
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	(4)
Decreases due to Lapses of Applicable Statute of Limitations	0	0	0
Total Amount of Unrecognized Tax Benefits at December	142	128	111
Accumulated Deferred Income Taxes Associated with Unrecognized Tax Benefits	(72)	(74)	(68)
Regulatory Asset-Unrecognized Tax Benefits	0	0	0
Amount of unrecognized tax benefits that would affect the effective tax rate	70	54	43
PSE&G [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Total Amount of Unrecognized Tax Benefits at January	140	181	165
Increases as a Result of Positions Taken in a Prior Period	15	3	55
Decreases as a Result of Positions Taken in a Prior Period	(11)	(23)	(43)
Increases as a Result of Positions Taken during the Current Period	5	6	5
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	(13)	(27)	0
Total Amount of Unrecognized Tax Benefits at December	135	140	181
Accumulated Deferred Income Taxes Associated with Unrecognized Tax Benefits	(73)	(106)	(162)
Regulatory Asset-Unrecognized Tax Benefits	(56)	(31)	(27)
Amount of unrecognized tax benefits that would affect the effective tax rate	6	3	(8)
Energy Holdings [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Total Amount of Unrecognized Tax Benefits at January	57	93	95
Increases as a Result of Positions Taken in a Prior Period	8	2	4
Decreases as a Result of Positions Taken in a Prior Period	(13)	(38)	(1)
Increases as a Result of Positions Taken during the Current Period	1	0	0
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	(5)
Decreases due to Lapses of Applicable Statute of Limitations	0	0	0
Total Amount of Unrecognized Tax Benefits at December	53	57	93
Accumulated Deferred Income Taxes Associated with Unrecognized Tax Benefits	(12)	(20)	(34)
Regulatory Asset-Unrecognized Tax Benefits	0	0	0
Amount of unrecognized tax benefits that would affect the effective tax rate	$ 41	$ 37	$ 59