Commitments And Contingent Liabilities (Guaranteed Obligations) (Detail) - PSEG Power [Member] - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Loss Contingencies [Line Items]
Face Value of Outstanding Guarantees	$ 1,704	$ 1,792
Exposure under Current Guarantees	245	128
Letters of Credit Margin Posted	85	128
Letters of Credit Margin Received	27	45
Counterparty Cash Collateral Deposited	61	0
Counterparty Cash Collateral Received	(1)	(5)
Net Broker Balance Deposited (Received)	939	59
Other Letters of Credit	$ 40	$ 42