Income Taxes (Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Total Amount of Unrecognized Tax Benefits at January	$ 318	$ 334	$ 328
Increases as a Result of Positions Taken in a Prior Period	17	11	40
Decreases as a Result of Positions Taken in a Prior Period	(37)	(70)	(32)
Increases as a Result of Positions Taken during the Current Period	27	52	12
Decreases as a Result of Positions Taken during the Current Period	0	(3)	(1)
Decreases as a Result of Settlements with Taxing Authorities	(4)	(6)	0
Decreases due to Lapses of Applicable Statute of Limitations	0	0	(13)
Total Amount of Unrecognized Tax Benefits at December	321	318	334
Accumulated Deferred Income Taxes Associated with Unrecognized Tax Benefits	(184)	(173)	(157)
Regulatory Asset-Unrecognized Tax Benefits	(46)	(46)	(56)
Amount of unrecognized tax benefits that would affect the effective tax rate	91	99	121
PSEG Power LLC
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Total Amount of Unrecognized Tax Benefits at January	151	142	128
Increases as a Result of Positions Taken in a Prior Period	8	4	18
Decreases as a Result of Positions Taken in a Prior Period	(13)	(37)	(10)
Increases as a Result of Positions Taken during the Current Period	15	48	6
Decreases as a Result of Positions Taken during the Current Period	0	0	0
Decreases as a Result of Settlements with Taxing Authorities	0	(6)	0
Decreases due to Lapses of Applicable Statute of Limitations	0	0	0
Total Amount of Unrecognized Tax Benefits at December	161	151	142
Accumulated Deferred Income Taxes Associated with Unrecognized Tax Benefits	(105)	(104)	(72)
Regulatory Asset-Unrecognized Tax Benefits	0	0	0
Amount of unrecognized tax benefits that would affect the effective tax rate	56	47	70
Public Service Electric and Gas Company
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Total Amount of Unrecognized Tax Benefits at January	108	135	140
Increases as a Result of Positions Taken in a Prior Period	5	4	15
Decreases as a Result of Positions Taken in a Prior Period	(1)	(31)	(11)
Increases as a Result of Positions Taken during the Current Period	12	3	5
Decreases as a Result of Positions Taken during the Current Period	0	(3)	(1)
Decreases as a Result of Settlements with Taxing Authorities	0	0	0
Decreases due to Lapses of Applicable Statute of Limitations	0	0	(13)
Total Amount of Unrecognized Tax Benefits at December	124	108	135
Accumulated Deferred Income Taxes Associated with Unrecognized Tax Benefits	(71)	(57)	(73)
Regulatory Asset-Unrecognized Tax Benefits	(46)	(46)	(56)
Amount of unrecognized tax benefits that would affect the effective tax rate	7	5	6
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	54	53	57
Increases as a Result of Positions Taken in a Prior Period	5	3	8
Decreases as a Result of Positions Taken in a Prior Period	(22)	(2)	(13)
Increases as a Result of Positions Taken during the Current Period	0	0	1
Decreases as a Result of Positions Taken during the Current Period	0	0	0
Decreases as a Result of Settlements with Taxing Authorities	(4)	0	0
Decreases due to Lapses of Applicable Statute of Limitations	0	0	0
Total Amount of Unrecognized Tax Benefits at December	33	54	53
Accumulated Deferred Income Taxes Associated with Unrecognized Tax Benefits	(7)	(12)	(12)
Regulatory Asset-Unrecognized Tax Benefits	0	0	0
Amount of unrecognized tax benefits that would affect the effective tax rate	$ 26	$ 42	$ 41