Fair Value Measurements (Fair Value Of Debt) (Detail) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Carrying Amount	$ 16,775	$ 16,180
Long-Term Debt, Fair Value	18,331	19,143
Power - Recourse Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Carrying Amount	2,343	2,342
Long-Term Debt, Fair Value	2,623	2,679
Public Service Electric and Gas Company [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Carrying Amount	11,502	10,909
Long-Term Debt, Fair Value	12,695	13,372
PSEG [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Carrying Amount	2,930	2,929
Long-Term Debt, Fair Value	$ 3,013	$ 3,092