Fair Value Measurements (Narrative) (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
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net assets measured at fair value on a recurring basis	$ 2,900	$ 2,500	$ 2,900		$ 2,500
Net assets measured at fair value on a recurring basis measured using unobservable input and as Level 3	10	4	10		4
Net Derivative Assets [Member] | PSEG Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Issuances (Settlements)	(5)	$ (2)	(6)	[1]	$ (6)	[1]
Nuclear Decommissioning Trust (NDT) Fund [Member] | PSEG Power [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
NDT Fund Foreign Currency	$ 1		$ 1				$ 2

[1] 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.