Commitments And Contingent Liabilities (Guaranteed Obligations) (Detail) - PSEG Power [Member] - USD ($) $ in Millions	Sep. 30, 2020	Dec. 31, 2019
Loss Contingencies [Line Items]
Face Value of Outstanding Guarantees	$ 1,828	$ 1,854
Exposure under Current Guarantees	86	171
Letters of Credit Margin Posted	135	121
Letters of Credit Margin Received	42	29
Counterparty Cash Collateral Deposited	0	0
Counterparty Cash Collateral Received	(1)	(4)
Net Broker Balance Deposited (Received)	57	48
Other Letters of Credit	$ 52	$ 82