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, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Jan. 01, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect Adjustment					$ (2)	$ 81
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	$ (481)	$ (441)	$ (489)	$ (377)	(377)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	30	8	40	21
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	(4)	1	(6)	5
Other Comprehensive Income (Loss), net of tax	26	9	34	26
Accumulated Other Comprehensive Income (Loss), Ending Balance	(455)	(432)	(455)	(432)	(489)
Net Change in Accumulated Other Comprehensive Income				(55)
Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect Adjustment						0
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	(18)	(5)	(15)	(1)	(1)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	(13)	(4)	(17)	(17)
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	3	0	4	0	3
Other Comprehensive Income (Loss), net of tax	3	(13)	0	(17)
Accumulated Other Comprehensive Income (Loss), Ending Balance	(15)	(18)	(15)	(18)	(15)
Net Change in Accumulated Other Comprehensive Income				(17)
Pension and OPEB Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect Adjustment						81
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	(496)	(441)	(499)	(360)	(360)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	0	0	(3)
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	3	4	6	7
Other Comprehensive Income (Loss), net of tax	3	4	6	4
Accumulated Other Comprehensive Income (Loss), Ending Balance	(493)	(437)	(493)	(437)	(499)
Net Change in Accumulated Other Comprehensive Income				(77)
Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect Adjustment						0
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	33	5	25	(16)	(16)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	30	21	44	41
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	(10)	(3)	(16)	(2)
Other Comprehensive Income (Loss), net of tax	20	18	28	39
Accumulated Other Comprehensive Income (Loss), Ending Balance	53	23	53	23	25
Net Change in Accumulated Other Comprehensive Income				39
PSEG Power [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect Adjustment						69
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	(392)	(372)	(401)	(319)	(319)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	24	17	35	29
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	(6)	1	(8)	5
Other Comprehensive Income (Loss), net of tax	18	18	27	34
Accumulated Other Comprehensive Income (Loss), Ending Balance	(374)	(354)	(374)	(354)	(401)
Net Change in Accumulated Other Comprehensive Income				(35)
PSEG Power [Member] | Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect Adjustment						0
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
Net Change in Accumulated Other Comprehensive Income				0
PSEG Power [Member] | Pension and OPEB Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect Adjustment						69
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	(418)	(375)	(420)	(306)	(306)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	0	0	(3)
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	3	3	5	6
Other Comprehensive Income (Loss), net of tax	3	3	5	3
Accumulated Other Comprehensive Income (Loss), Ending Balance	(415)	(372)	(415)	(372)	(420)
Net Change in Accumulated Other Comprehensive Income				(66)
PSEG Power [Member] | Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect Adjustment						$ 0
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	26	3	19	(13)	(13)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	24	17	35	32
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	(9)	(2)	(13)	(1)
Other Comprehensive Income (Loss), net of tax	15	15	22	31
Accumulated Other Comprehensive Income (Loss), Ending Balance	$ 41	$ 18	$ 41	18	$ 19
Net Change in Accumulated Other Comprehensive Income				$ 31