Income Taxes (Narrative) (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2021 USD ($)
Income Taxes [Line Items]
Effective Income Tax Rate, Federal and State Statutory Income Tax Rate, Percent	28.11%
NJ tax surcharge percent for 2018 to 2019	1.50%
NJ tax surcharge percent for 2020 to 2021	2.50%
NJ tax surcharge percent through 2023	2.50%
Public Service Electric and Gas Company [Member]
Income Taxes [Line Items]
Operating Loss Carryforwards	$ 14