Financial Risk Management Activities (Schedule Of Derivative Instruments Fair Value In Balance Sheets) (Detail) - USD ($) $ in Millions		Sep. 30, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Derivative Contracts, Current Assets		$ 46	$ 113
Derivative Contracts, Noncurrent Assets		17	24
Total Mark-to-Market Derivative Assets		63	137
Derivative Contracts, Current Liabilities		(8)	(36)
Derivative Contracts, Noncurrent Liabilities		(1)	(1)
Total Mark-to-Market Derivative (Liabilities)		(9)	(37)
Net Mark-to-Market Derivative Assets (Liabilities)		54	100
PSEG Power [Member]
Derivatives, Fair Value [Line Items]
Collateral Already Posted, Aggregate Fair Value		56	44
Derivative Contracts, Current Assets	[1]	46	113
Derivative Contracts, Noncurrent Assets	[1]	17	24
Total Mark-to-Market Derivative Assets	[1]	63	137
Derivative Contracts, Current Liabilities	[1]	(6)	(31)
Derivative Contracts, Noncurrent Liabilities	[1]	(1)	(1)
Total Mark-to-Market Derivative (Liabilities)	[1]	(7)	(32)
Net Mark-to-Market Derivative Assets (Liabilities)	[1]	56	105
Derivative, Fair Value, Amount Offset Against Collateral, Net	[1],[2]	(1)	(2)
Other Noncurrent Liabilities [Member] | PSEG Power [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net		11
Other Current Assets [Member] | PSEG Power [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net		(11)	(1)
Other Noncurrent Assets [Member] | PSEG Power [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net		(1)	(1)
Energy-Related Contracts [Member] | Not Designated as Hedging Instrument [Member] | PSEG Power [Member]
Derivatives, Fair Value [Line Items]
Derivative Contracts, Current Assets	[1]	383	636
Derivative Contracts, Noncurrent Assets	[1]	133	163
Total Mark-to-Market Derivative Assets	[1]	516	799
Derivative Contracts, Current Liabilities	[1]	(333)	(553)
Derivative Contracts, Noncurrent Liabilities	[1]	(126)	(139)
Total Mark-to-Market Derivative (Liabilities)	[1]	(459)	(692)
Net Mark-to-Market Derivative Assets (Liabilities)	[1]	57	107
Energy-Related Contracts [Member] | Other Noncurrent Liabilities [Member] | PSEG Power [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net	[1],[2]	125	138
Energy-Related Contracts [Member] | Other Current Assets [Member] | PSEG Power [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net	[1],[2]	(337)	(523)
Energy-Related Contracts [Member] | Other Noncurrent Assets [Member] | PSEG Power [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net	[1],[2]	(116)	(139)
Energy-Related Contracts [Member] | Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net	[3]	(453)	(662)
Energy-Related Contracts [Member] | Assets [Member] | PSEG Power [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net	[1],[2],[3]	(453)	(662)
Energy-Related Contracts [Member] | Other Current Liabilities [Member] | PSEG Power [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net	[1],[2]	327	522
Energy-Related Contracts [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net	[3]	452	660
Energy-Related Contracts [Member] | Other Liabilities [Member] | PSEG Power [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net	[1],[2],[3]	452	660
Interest Rate Swap [Member] | PSEG [Member] | Fair Value Hedging [Member]
Derivatives, Fair Value [Line Items]
Derivative Contracts, Current Assets	[1]	0	0
Derivative Contracts, Noncurrent Assets	[1]	0	0
Total Mark-to-Market Derivative Assets	[1]	0	0
Derivative Contracts, Current Liabilities	[1]	(2)	(5)
Derivative Contracts, Noncurrent Liabilities	[1]	0	0
Total Mark-to-Market Derivative (Liabilities)	[1]	(2)	(5)
Net Mark-to-Market Derivative Assets (Liabilities)	[1]	(2)	(5)
Interest Rate Swap [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net		$ 0	$ 0

[1] Substantially all of PSEG Power’s and PSEG’s derivative instruments are contracts subject to master netting agreements. Contracts not subject to master netting or similar agreements are immaterial and did not have any collateral posted or received as of September 30, 2020 and December 31, 2019.

[2] Represents the netting of fair value balances with the same counterparty (where the right of offset exists) and the application of collateral. All cash collateral (received) posted that has been allocated to derivative positions, where the right of offset exists, has been offset on the Condensed Consolidated Balance Sheets. As of September 30, 2020 and December 31, 2019, PSEG Power had net cash collateral (receipts) payments to counterparties of $56 million and $44 million, respectively. Of these net cash collateral (receipts) payments, $(1) million and $(2) million as of September 30, 2020 and December 31, 2019, respectively, were netted against the corresponding net derivative contract positions. Of the $(1) million as of September 30, 2020, $(11) million was netted against current assets, $(1) million was netted against noncurrent assets, and $11 million was netted against noncurrent liabilities. Of the $(2) million as of December 31, 2019, $(1) million was netted against current assets and $(1) million was netted against noncurrent assets

[3] Represents the netting of fair value balances with the same counterparty (where the right of offset exists) and the application of collateral. See Note 13. Financial Risk Management Activities for additional detail.