Accumulated Other Comprehensive Income (Loss), Net of Tax (Reclassifications 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
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	$ 9	$ (2)	$ 12	$ (8)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Tax	(5)	1	(6)	3
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	4	(1)	6	(5)
Cash Flow Hedges [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	(4)	(1)	(6)	(1)	$ (4)
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	(3)	0	(4)	0	$ (3)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax	(1)	(1)	(2)	(1)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	(3)	0	(4)	0
Pension and OPEB Plans [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Reclassification Adjustment from AOCI, Pension and OPEB, Pre-Tax	(4)	(5)	(8)	(10)
Reclassification Adjustment from AOCI, Pension and OPEB, Tax	1	1	2	3
Reclassification Adjustment from AOCI, Pension and OPEB, After-Tax	(3)	(4)	(6)	(7)
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	(3)	(4)	(6)	(7)
Available-for-Sale Securities [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Reclassification for Available for Sale Securities, Pre-Tax	17	4	26	3
Reclassification for Available for Sale Securities, Tax	(7)	(1)	(10)	(1)
Reclassification for Available for Sale Securities, After-Tax	10	3	16	2
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	10	3	16	2
PSEG Power [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	11	(1)	15	(6)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Tax	(5)	0	(7)	1
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	6	(1)	8	(5)
PSEG Power [Member] | Cash Flow Hedges [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	0	0	0	0
PSEG Power [Member] | Pension and OPEB Plans [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Reclassification Adjustment from AOCI, Pension and OPEB, Pre-Tax	(3)	(4)	(6)	(8)
Reclassification Adjustment from AOCI, Pension and OPEB, Tax	0	1	1	2
Reclassification Adjustment from AOCI, Pension and OPEB, After-Tax	(3)	(3)	(5)	(6)
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	(3)	(3)	(5)	(6)
PSEG Power [Member] | Available-for-Sale Securities [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Reclassification for Available for Sale Securities, Pre-Tax	14	3	21	2
Reclassification for Available for Sale Securities, Tax	(5)	(1)	(8)	(1)
Reclassification for Available for Sale Securities, After-Tax	9	2	13	1
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	9	2	13	1
Interest Expense [Member] | Cash Flow Hedges [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	(4)	(1)	(6)	(1)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax	(1)	1	(2)	1
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	(3)	0	(4)	0
Non-Operating Pension and OPEB Credits (Costs) [Member] | Pension and OPEB Plans [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Amortization of Prior Service (Cost) Credit, Pre-Tax	6	6	12	13
Amortization of Prior Service (Cost) Credit, Tax	(1)	(2)	(3)	(4)
Amortization of Prior Service (Cost) Credit, After-Tax	5	4	9	9
Amortization of Actuarial Loss, Pre-Tax	(10)	(11)	(20)	(23)
Amortization of Actuarial Loss, Tax	2	3	5	7
Amortization of Actuarial Loss, After-Tax	(8)	(8)	(15)	(16)
Non-Operating Pension and OPEB Credits (Costs) [Member] | PSEG Power [Member] | Pension and OPEB Plans [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Amortization of Prior Service (Cost) Credit, Pre-Tax	6	5	11	11
Amortization of Prior Service (Cost) Credit, Tax	(2)	(1)	(3)	(3)
Amortization of Prior Service (Cost) Credit, After-Tax	4	4	8	8
Amortization of Actuarial Loss, Pre-Tax	(9)	(9)	(17)	(19)
Amortization of Actuarial Loss, Tax	2	2	4	5
Amortization of Actuarial Loss, After-Tax	(7)	(7)	(13)	(14)
Net Gains (Losses) on Trust Investments [Member] | Available-for-Sale Securities [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Reclassification for Available for Sale Securities, Pre-Tax	17	4	26	3
Reclassification for Available for Sale Securities, Tax	(7)	(1)	(10)	(1)
Reclassification for Available for Sale Securities, After-Tax	10	3	16	2
Net Gains (Losses) on Trust Investments [Member] | PSEG Power [Member] | Available-for-Sale Securities [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Reclassification for Available for Sale Securities, Pre-Tax	14	3	21	2
Reclassification for Available for Sale Securities, Tax	(5)	(1)	(8)	(1)
Reclassification for Available for Sale Securities, After-Tax	$ 9	$ 2	$ 13	$ 1