Fair Value Measurements (Changes In Level 3 Assets And (Liabilities) Measured At Fair Value On A Recurring Basis) (Detail) - USD ($) $ in Millions		3 Months Ended			6 Months Ended
		Jun. 30, 2020		Jun. 30, 2019	Jun. 30, 2020		Jun. 30, 2019		Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
PSEG Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Included in Income		$ (4)		$ 8	$ 9		$ 9
Fair Value, Net Derivative Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss)		(9)		6	3		3
Net Derivative Assets (Liabilities) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Closing Balance		10			10
Net Derivative Assets (Liabilities) [Member] | PSEG Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value									$ 7	$ (2)	$ 1
Opening Balance		19
Included in Income		4	[1]	(8)	9	[1]	9	[1]
Purchases, (Sales)		0		0	0		0
Issuances (Settlements)		(5)		(2)	(6)	[2]	(6)	[2]
Transfers In (Out)	[3]	0		0	0		0
Closing Balance		10		4	10		4
Operating Revenues [Member] | PSEG Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Included in Income		(4)		11	14		17
Fair Value, Net Derivative Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss)		(9)		9	2		9
Energy Costs [Member] | PSEG Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Included in Income		0		(3)	1		(6)
Fair Value, Net Derivative Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss)		$ 0		$ (3)	$ (5)		$ (8)

[1] Unrealized gains (losses) in the following table represent the change in derivative assets and liabilities still held as of June 30, 2020 and 2019. .                                             Three Months Ended June 30,   Six Months Ended June 30,         2020   2019   2020   2019         Total Gains (Losses)   Unrealized Gains (Losses)   Total Gains (Losses)   Unrealized Gains (Losses)   Total Gains (Losses)   Unrealized Gains (Losses)   Total Gains (Losses)   Unrealized Gains (Losses)         Millions     PSEG and PSEG Power                                 Operating Revenues   $ (4 )   $ (9 )   $ 11
  $ 9
  $ 14
  $ 2
  $ 17
  $ 9
    Energy Costs   —
  —
  (3 )   (3 )   (5 )   1
  (8 )   (6 )     Total   $ (4 )   $ (9 )   $ 8
  $ 6
  $ 9
  $ 3
  $ 9
  $ 3
                                       

[2] settlements of $(5) million and $(6) million for the three months and six months ended June 30, 2020, respectively, and $(2) million and $(6) million for the three months and six months ended June 30, 2019, respectively.

[3] There were no transfers into or out of Level 3 during the three months and six months ended June 30, 2020 and 2019.