Commitments And Contingent Liabilities (Guaranteed Obligations) (Detail) - PSEG Power [Member] - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Loss Contingencies [Line Items]
Face Value of Outstanding Guarantees	$ 1,856	$ 1,854
Exposure under Current Guarantees	140	171
Letters of Credit Margin Posted	114	121
Letters of Credit Margin Received	94	29
Counterparty Cash Collateral Deposited	0	0
Counterparty Cash Collateral Received	(7)	(4)
Net Broker Balance Deposited (Received)	(4)	48
Other Letters of Credit	$ 82	$ 82