Commitments And Contingent Liabilities (Face Value Of Outstanding Guarantees, Current Exposure And Margin Positions) (Detail) - PSEG Power LLC - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Other Commitments [Line Items]
Face Value of Outstanding Guarantees	$ 1,854	$ 1,772
Exposure under Current Guarantees	171	198
Letters of Credit Margin Posted	121	115
Letters of Credit Margin Received	29	26
Counterparty Cash Margin Deposited	0	0
Counterparty Cash Margin Received	(4)	(10)
Net Broker Balance Deposited (Received)	48	403
Other Letters of Credit	$ 82	$ 52