Income Taxes (Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Total Amount of Unrecognized Tax Benefits at January	$ 321	$ 318	$ 334
Increases as a Result of Positions Taken in a Prior Period	33	17	11
Decreases as a Result of Positions Taken in a Prior Period	(91)	(37)	(70)
Increases as a Result of Positions Taken during the Current Period	0	27	52
Decreases as a Result of Positions Taken during the Current Period	0	0	(3)
Decreases as a Result of Settlements with Taxing Authorities	(116)	(4)	(6)
Decreases due to Lapses of Applicable Statute of Limitations	0	0	0
Total Amount of Unrecognized Tax Benefits at December	147	321	318
Accumulated Deferred Income Taxes Associated with Unrecognized Tax Benefits	(69)	(184)	(173)
Regulatory Asset-Unrecognized Tax Benefits	(15)	(46)	(46)
Amount of unrecognized tax benefits that would affect the effective tax rate	63	91	99
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	161	151	142
Increases as a Result of Positions Taken in a Prior Period	10	8	4
Decreases as a Result of Positions Taken in a Prior Period	(36)	(13)	(37)
Increases as a Result of Positions Taken during the Current Period	0	15	48
Decreases as a Result of Positions Taken during the Current Period	0	0	0
Decreases as a Result of Settlements with Taxing Authorities	(52)	0	(6)
Decreases due to Lapses of Applicable Statute of Limitations	0	0	0
Total Amount of Unrecognized Tax Benefits at December	83	161	151
Accumulated Deferred Income Taxes Associated with Unrecognized Tax Benefits	(49)	(105)	(104)
Regulatory Asset-Unrecognized Tax Benefits	0	0	0
Amount of unrecognized tax benefits that would affect the effective tax rate	34	56	47
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	124	108	135
Increases as a Result of Positions Taken in a Prior Period	21	5	4
Decreases as a Result of Positions Taken in a Prior Period	(51)	(1)	(31)
Increases as a Result of Positions Taken during the Current Period	0	12	3
Decreases as a Result of Positions Taken during the Current Period	0	0	(3)
Decreases as a Result of Settlements with Taxing Authorities	(64)	0	0
Decreases due to Lapses of Applicable Statute of Limitations	0	0	0
Total Amount of Unrecognized Tax Benefits at December	30	124	108
Accumulated Deferred Income Taxes Associated with Unrecognized Tax Benefits	(12)	(71)	(57)
Regulatory Asset-Unrecognized Tax Benefits	(15)	(46)	(46)
Amount of unrecognized tax benefits that would affect the effective tax rate	3	7	5
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	33	54	53
Increases as a Result of Positions Taken in a Prior Period	1	5	3
Decreases as a Result of Positions Taken in a Prior Period	(4)	(22)	(2)
Increases as a Result of Positions Taken during the Current Period	0	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	(4)	0
Decreases due to Lapses of Applicable Statute of Limitations	0	0	0
Total Amount of Unrecognized Tax Benefits at December	30	33	54
Accumulated Deferred Income Taxes Associated with Unrecognized Tax Benefits	(8)	(7)	(12)
Regulatory Asset-Unrecognized Tax Benefits	0	0	0
Amount of unrecognized tax benefits that would affect the effective tax rate	$ 22	$ 26	$ 42