Accumulated Other Comprehensive Income (Loss), Net of Tax (Changes of AOCI) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Jan. 01, 2019	Jan. 01, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption						$ (81)	$ (176)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	$ (432)	$ (410)	$ (377)	$ (229)	$ (229)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(7)	(6)	14	(29)
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	1	9	6	27
Other Comprehensive Income (Loss), net of tax	(6)	3	20	(2)
Accumulated Other Comprehensive Income (Loss), Ending Balance	(438)	(407)	(438)	(407)	(377)
Net Change in Accumulated Other Comprehensive Income			(61)	(178)
Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption						0	0
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	(18)	(1)	(1)	0	0
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0	0	(17)	(1)	(1)
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	1	0	1	0	0
Other Comprehensive Income (Loss), net of tax	1	0	(16)	(1)
Accumulated Other Comprehensive Income (Loss), Ending Balance	(17)	(1)	(17)	(1)	(1)
Net Change in Accumulated Other Comprehensive Income			(16)	(1)
Pension and OPEB Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption						(81)	0
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	(437)	(391)	(360)	(406)	(406)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(20)	0	(23)	0
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	3	7	10	22
Other Comprehensive Income (Loss), net of tax	(17)	7	(13)	22
Accumulated Other Comprehensive Income (Loss), Ending Balance	(454)	(384)	(454)	(384)	(360)
Net Change in Accumulated Other Comprehensive Income			(94)	22
Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption						0	(176)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	23	(18)	(16)	177	177
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	13	(6)	54	(28)
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	(3)	2	(5)	5
Other Comprehensive Income (Loss), net of tax	10	(4)	49	(23)
Accumulated Other Comprehensive Income (Loss), Ending Balance	33	(22)	33	(22)	(16)
Net Change in Accumulated Other Comprehensive Income			49	(199)
PSEG Power [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption						(69)	(175)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	(354)	(350)	(319)	(172)	(172)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(4)	(5)	25	(23)
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	(1)	8	4	23
Other Comprehensive Income (Loss), net of tax	(5)	3	29	0
Accumulated Other Comprehensive Income (Loss), Ending Balance	(359)	(347)	(359)	(347)	(319)
Net Change in Accumulated Other Comprehensive Income			(40)	(175)
PSEG Power [Member] | Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption						0	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	0
PSEG Power [Member] | Pension and OPEB Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption						(69)	0
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	(372)	(335)	(306)	(347)	(347)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(14)	0	(17)	0
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	2	7	8	19
Other Comprehensive Income (Loss), net of tax	(12)	7	(9)	19
Accumulated Other Comprehensive Income (Loss), Ending Balance	(384)	(328)	(384)	(328)	(306)
Net Change in Accumulated Other Comprehensive Income			(78)	19
PSEG Power [Member] | Available-for-Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cumulative Effect of New Accounting Principle in Period of Adoption						$ 0	$ (175)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Beginning Balance	18	(15)	(13)	175	175
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	10	(5)	42	(23)
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	(3)	1	(4)	4
Other Comprehensive Income (Loss), net of tax	7	(4)	38	(19)
Accumulated Other Comprehensive Income (Loss), Ending Balance	$ 25	$ (19)	25	(19)	$ (13)
Net Change in Accumulated Other Comprehensive Income			$ 38	$ (194)