Fair Value Measurements (Fair Value Of Debt) (Detail) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Carrying Amount	$ 15,695	$ 16,180
Long-Term Debt, Fair Value	17,800	19,143
Power - Recourse Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Carrying Amount	1,394	2,342
Long-Term Debt, Fair Value	1,679	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	11,370	10,909
Long-Term Debt, Fair Value	13,090	13,372
PSEG [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Carrying Amount	2,931	2,929
Long-Term Debt, Fair Value	$ 3,031	$ 3,092