Accumulated Other Comprehensive Income (Loss), Net of Tax (Changes of AOCI) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 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	$ (489)	$ (377)	(377)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	10	13
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	(2)	4
Other Comprehensive Income (Loss), net of tax	8	17
Accumulated Other Comprehensive Income (Loss), Ending Balance	(481)	(441)	(489)
Net Change in Accumulated Other Comprehensive Income		(64)
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	(15)	(1)	(1)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(4)	(4)	(17)
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	1	0	3
Other Comprehensive Income (Loss), net of tax	(3)	(4)
Accumulated Other Comprehensive Income (Loss), Ending Balance	(18)	(5)	(15)
Net Change in Accumulated Other Comprehensive Income		(4)
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	(499)	(360)	(360)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	(3)
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	3	3
Other Comprehensive Income (Loss), net of tax	3	0
Accumulated Other Comprehensive Income (Loss), Ending Balance	(496)	(441)	(499)
Net Change in Accumulated Other Comprehensive Income		(81)
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	25	(16)	(16)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	14	20
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	(6)	1
Other Comprehensive Income (Loss), net of tax	8	21
Accumulated Other Comprehensive Income (Loss), Ending Balance	33	5	25
Net Change in Accumulated Other Comprehensive Income		21
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	(401)	(319)	(319)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	11	12
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	(2)	4
Other Comprehensive Income (Loss), net of tax	9	16
Accumulated Other Comprehensive Income (Loss), Ending Balance	(392)	(372)	(401)
Net Change in Accumulated Other Comprehensive Income		(53)
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
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	0
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	0	0
Other Comprehensive Income (Loss), net of tax	0	0
Accumulated Other Comprehensive Income (Loss), Ending Balance	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	(420)	(306)	(306)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	(3)
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	2	3
Other Comprehensive Income (Loss), net of tax	2	0
Accumulated Other Comprehensive Income (Loss), Ending Balance	(418)	(375)	(420)
Net Change in Accumulated Other Comprehensive Income		(69)
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	19	(13)	(13)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	11	15
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	(4)	1
Other Comprehensive Income (Loss), net of tax	7	16
Accumulated Other Comprehensive Income (Loss), Ending Balance	$ 26	3	$ 19
Net Change in Accumulated Other Comprehensive Income		$ 16