Accumulated Other Comprehensive Income (Loss), Net of Tax (Changes of AOCI) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	$ (542)	$ (481)	$ (504)	$ (489)	$ (489)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	16	30	(24)	40
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	4	(4)	6	(6)
Other Comprehensive Income (Loss), net of tax	20	26	(18)	34
Accumulated Other Comprehensive Income (Loss), Ending Balance	(522)	(455)	(522)	(455)	(504)
Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	(8)	(18)	(9)	(15)	(15)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	0	0	(4)	(4)
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	0	3	1	4	10
Other Comprehensive Income (Loss), net of tax	0	3	1	0
Accumulated Other Comprehensive Income (Loss), Ending Balance	(8)	(15)	(8)	(15)	(9)
Pension and OPEB Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	(542)	(496)	(545)	(499)	(499)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	0	0	0
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	4	3	7	6
Other Comprehensive Income (Loss), net of tax	4	3	7	6
Accumulated Other Comprehensive Income (Loss), Ending Balance	(538)	(493)	(538)	(493)	(545)
Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	8	33	50	25	25
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	16	30	(24)	44
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	0	(10)	(2)	(16)
Other Comprehensive Income (Loss), net of tax	16	20	(26)	28
Accumulated Other Comprehensive Income (Loss), Ending Balance	24	53	24	53	50
PSEG Power [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	(449)	(392)	(419)	(401)	(401)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	13	24	(18)	35
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	2	(6)	3	(8)
Other Comprehensive Income (Loss), net of tax	15	18	(15)	27
Accumulated Other Comprehensive Income (Loss), Ending Balance	(434)	(374)	(434)	(374)	(419)
PSEG Power [Member] | Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	0	0	0	0	0
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	0	0	0
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	0	0	0	0
Other Comprehensive Income (Loss), net of tax	0	0	0	0
Accumulated Other Comprehensive Income (Loss), Ending Balance	0	0	0	0	0
PSEG Power [Member] | Pension and OPEB Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	(457)	(418)	(459)	(420)	(420)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	0	0	0
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	3	3	5	5
Other Comprehensive Income (Loss), net of tax	3	3	5	5
Accumulated Other Comprehensive Income (Loss), Ending Balance	(454)	(415)	(454)	(415)	(459)
PSEG Power [Member] | Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	8	26	40	19	19
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	13	24	(18)	35
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	(1)	(9)	(2)	(13)
Other Comprehensive Income (Loss), net of tax	12	15	(20)	22
Accumulated Other Comprehensive Income (Loss), Ending Balance	$ 20	$ 41	$ 20	$ 41	$ 40