Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated Other Comprehensive Income (Loss), Net of Tax (Reclassifications out of AOCI) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amount Reclassified from Accumulated Other Comprehensive Income, Pre-Tax	$ 12	$ (8)	$ (54)
Amount Reclassified from Accumulated Other Comprehensive Income, Tax	(8)	1	17
Amount Reclassified from Accumulated Other Comprehensive Income, After-Tax	4	(7)	(37)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amount Reclassified from AOCI for Available for Sale Securities, Pre-Tax	42	13	(13)
Amount Reclassified from AOCI for Available for Sale Securities, Tax	(16)	(5)	5
Amount Reclassified from AOCI for Available for Sale Securities, After-Tax	26	8	(8)
Amount Reclassified from Accumulated Other Comprehensive Income, After-Tax	26	8	(8)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amount Reclassified from AOCI for Pension and OPEB Plans, Pre-Tax	(16)	(17)	(41)
Amount Reclassified from AOCI for Pension and OPEB Plans, Tax	4	5	12
Amount Reclassified from AOCI for Pension and OPEB Plans, After-Tax	(12)	(12)	(29)
Amount Reclassified from Accumulated Other Comprehensive Income, After-Tax	(12)	(12)	(29)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amount Reclassified from AOCI for Cash Flow Hedges, Pre-Tax	(14)	(4)
Amount Reclassified from AOCI for Cash Flow Hedges, Tax	4	1
Amount Reclassified from AOCI for Cash Flow Hedges, After-Tax	(10)	(3)
Amount Reclassified from Accumulated Other Comprehensive Income, After-Tax	(10)	(3)	0
Net Gains (Losses) on Trust Investments [Member] | Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amount Reclassified from AOCI for Available for Sale Securities, Pre-Tax	42	13	(13)
Amount Reclassified from AOCI for Available for Sale Securities, Tax	(16)	(5)	5
Amount Reclassified from AOCI for Available for Sale Securities, After-Tax	26	8	(8)
Interest Expense [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amount Reclassified from AOCI for Cash Flow Hedges, Pre-Tax	(14)	(4)
Amount Reclassified from AOCI for Cash Flow Hedges, Tax	4	1
Amount Reclassified from AOCI for Cash Flow Hedges, After-Tax	(10)	(3)
Non-Operating Pension and OPEB Credits (Costs) [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of Prior Service (Cost) Credit, Pre-Tax	24	26	6
Amortization of Prior Service (Cost) Credit, Tax	(7)	(7)	(2)
Amortization of Prior Service (Cost) Credit, After-Tax	17	19	4
Amortization of Actuarial Loss, Pre-Tax	(40)	(43)	(47)
Amortization of Actuarial Loss, Tax	11	12	14
Amortization of Actuarial Loss, After-Tax	(29)	(31)	(33)
PSEG Power LLC
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amount Reclassified from Accumulated Other Comprehensive Income, Pre-Tax	21	(3)	(46)
Amount Reclassified from Accumulated Other Comprehensive Income, Tax	(10)	(1)	15
Amount Reclassified from Accumulated Other Comprehensive Income, After-Tax	11	(4)	(31)
PSEG Power LLC | Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amount Reclassified from AOCI for Available for Sale Securities, Pre-Tax	34	10	(11)
Amount Reclassified from AOCI for Available for Sale Securities, Tax	(14)	(4)	5
Amount Reclassified from AOCI for Available for Sale Securities, After-Tax	20	6	(6)
Amount Reclassified from Accumulated Other Comprehensive Income, After-Tax	20	6	(6)
PSEG Power LLC | Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amount Reclassified from AOCI for Pension and OPEB Plans, Pre-Tax	(13)	(13)	(35)
Amount Reclassified from AOCI for Pension and OPEB Plans, Tax	4	3	10
Amount Reclassified from AOCI for Pension and OPEB Plans, After-Tax	(9)	(10)	(25)
Amount Reclassified from Accumulated Other Comprehensive Income, After-Tax	(9)	(10)	(25)
PSEG Power LLC | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amount Reclassified from Accumulated Other Comprehensive Income, After-Tax	0	0	0
PSEG Power LLC | Net Gains (Losses) on Trust Investments [Member] | Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amount Reclassified from AOCI for Available for Sale Securities, Pre-Tax	34	10	(11)
Amount Reclassified from AOCI for Available for Sale Securities, Tax	(14)	(4)	5
Amount Reclassified from AOCI for Available for Sale Securities, After-Tax	20	6	(6)
PSEG Power LLC | Non-Operating Pension and OPEB Credits (Costs) [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of Prior Service (Cost) Credit, Pre-Tax	21	23	5
Amortization of Prior Service (Cost) Credit, Tax	(6)	(7)	(1)
Amortization of Prior Service (Cost) Credit, After-Tax	15	16	4
Amortization of Actuarial Loss, Pre-Tax	(34)	(36)	(40)
Amortization of Actuarial Loss, Tax	10	10	11
Amortization of Actuarial Loss, After-Tax	$ (24)	$ (26)	$ (29)