Trust Investments (Narrative) (Detail) - PSEG Power [Member] $ in Millions	3 Months Ended
	Mar. 31, 2021 USD ($) Facility		Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($)
Schedule of Trust Investments [Line Items]
Number of Nuclear Facilities | Facility	5
Nuclear Decommissioning Trust (NDT) Fund [Member]
Schedule of Trust Investments [Line Items]
NDT Fund Foreign Currency	$ 1			$ 2
Impairment of Debt Securities	0	[1]	$ (3)
Debt Securities [Member] | Nuclear Decommissioning Trust (NDT) Fund [Member]
Schedule of Trust Investments [Line Items]
After tax amount of net unrealized gains recognized in AOCI	8
Equity Securities [Member] | Nuclear Decommissioning Trust (NDT) Fund [Member]
Schedule of Trust Investments [Line Items]
Unrealized Gains (Losses) on Equity Securities still held	$ 24

[1] PSEG Power recognized an impairment of available-for-sale debt securities in 2020. PSEG Power’s policy is to sell all securities that are rated below investment grade.