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
		Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Included in Income		$ 1	$ (1)
Settlements		(4)	1
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Change in Unrealized Gain (Loss)		(3)	(1)
Net Derivative Assets (Liabilities) [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				$ 1	$ 7
Included in Income	[1]	1	(1)
Purchases, (Sales)		0	0
Issuances (Settlements)	[2]	(4)	1
Transfers In (Out)	[3]	0	0
Closing Balance		(2)	7
Operating Revenues [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Included in Income		6	8
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Change in Unrealized Gain (Loss)		0	8
Energy Costs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Included in Income		(5)	(9)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Change in Unrealized Gain (Loss)		$ (3)	$ (9)

[1] Unrealized gains (losses) in the following table represent the change in derivative assets and liabilities still held as of March 31, 2019 and 2018. Three Months Ended March 31, 2019 2018 Total Gains (Losses) Unrealized Gains (Losses) Total Gains (Losses) Unrealized Gains (Losses) Millions PSEG and Power Operating Revenues $6 $— $8 $8 Energy Costs (5) (3) (9) (9) Total $1 $(3) $(1) $(1)

[2] Represents settlements of $(4) million and $1 million for the three months ended March 31, 2019 and 2018.

[3] There were no transfers into or out of Level 3 during the three months ended March 31, 2019 and 2018.