Financial Risk Management Activities (Schedule Of Derivative Instruments Fair Value In Balance Sheets) (Detail) - USD ($) $ in Millions		Mar. 31, 2019		Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Collateral Already Posted, Aggregate Fair Value		$ 203		$ 393
Derivative Contracts, Current Assets		20		11
Derivative Contracts, Noncurrent Assets		4		1
Total Mark-to-Market Derivative Assets		24		12
Derivative Contracts, Current Liabilities		(13)		(11)
Derivative Contracts, Noncurrent Liabilities		(7)		(4)
Total Mark-to-Market Derivative (Liabilities)		(20)		(15)
Net Mark-to-Market Derivative Assets (Liabilities)		4		(3)
Derivative, Fair Value, Amount Offset Against Collateral, Net		48		153
Power [Member]
Derivatives, Fair Value [Line Items]
Derivative Contracts, Current Assets	[1]	19		11
Derivative Contracts, Noncurrent Assets	[1]	4		1
Total Mark-to-Market Derivative Assets		23		12
Derivative Contracts, Current Liabilities	[1]	(13)		(11)
Derivative Contracts, Noncurrent Liabilities	[1]	(1)		(4)
Total Mark-to-Market Derivative (Liabilities)		(14)		(15)
Net Mark-to-Market Derivative Assets (Liabilities)		9	[1]	(3)
Derivative, Fair Value, Amount Offset Against Collateral, Net		48	[1],[2]	153
Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net				62
Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net				(2)
Other Noncurrent Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net		(9)
Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net		57		96
Energy-Related Contracts [Member] | Not Designated as Hedging Instrument [Member] | Power [Member]
Derivatives, Fair Value [Line Items]
Derivative Contracts, Current Assets	[1]	346		426
Derivative Contracts, Noncurrent Assets	[1]	180		137
Total Mark-to-Market Derivative Assets		526		563
Derivative Contracts, Current Liabilities	[1]	(396)		(521)
Derivative Contracts, Noncurrent Liabilities	[1]	(169)		(198)
Total Mark-to-Market Derivative (Liabilities)		(565)		(719)
Net Mark-to-Market Derivative Assets (Liabilities)		(39)	[1]	(156)
Energy-Related Contracts [Member] | Other Noncurrent Liabilities [Member] | Power [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net	[1],[2]	168		194
Energy-Related Contracts [Member] | Other Current Assets [Member] | Power [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net	[1],[2]	(327)		(415)
Energy-Related Contracts [Member] | Other Noncurrent Assets [Member] | Power [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net	[1],[2]	(176)		(136)
Energy-Related Contracts [Member] | Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net	[3]	(503)		(551)
Energy-Related Contracts [Member] | Assets [Member] | Power [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net	[3]	(503)		(551)
Energy-Related Contracts [Member] | Other Current Liabilities [Member] | Power [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net	[1],[2]	383		510
Energy-Related Contracts [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net	[3]	551		704
Energy-Related Contracts [Member] | Other Liabilities [Member] | Power [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net	[3]	551		$ 704
Interest Rate Swap [Member] | PSEG [Member] | Fair Value Hedging [Member]
Derivatives, Fair Value [Line Items]
Derivative Contracts, Current Assets	[1]	1
Derivative Contracts, Noncurrent Assets	[1]	0
Total Mark-to-Market Derivative Assets		1
Derivative Contracts, Current Liabilities	[1]	0
Derivative Contracts, Noncurrent Liabilities	[1]	(6)
Total Mark-to-Market Derivative (Liabilities)		(6)
Net Mark-to-Market Derivative Assets (Liabilities)	[1]	(5)
Interest Rate Swap [Member] | Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net	[3]	0
Interest Rate Swap [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative, Fair Value, Amount Offset Against Collateral, Net	[3]	$ 0

[1] Substantially all of 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 March 31, 2019 and December 31, 2018.

[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 or 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 March 31, 2019 and December 31, 2018, Power had net cash collateral/margin payments to counterparties of $203 million and $393 million, respectively. Of these net cash/collateral margin payments, $48 million as of March 31, 2019 and $153 million as December 31, 2018 were netted against the corresponding net derivative contract positions. Of the $48 million as of March 31, 2019, $(9) million was netted against noncurrent assets and $57 million was netted against current liabilities. Of the $153 million as of December 31, 2018, $(2) million was netted against current assets, $(3) million was netted against noncurrent assets, $96 million was netted against current liabilities and $62 million was netted against noncurrent liabilities.

[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.