Commitments And Contingent Liabilities (Face Value Of Outstanding Guarantees, Current Exposure And Margin Positions) (Detail) - Power [Member] - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Other Commitments [Line Items]
Face Value of Outstanding Guarantees	$ 1,734	$ 1,814
Exposure under Current Guarantees	172	273
Letters of Credit Margin Posted	122	159
Letters of Credit Margin Received	192	40
Counterparty Cash Margin Deposited	0	0
Counterparty Cash Margin Received	(15)	(13)
Net Broker Balance Deposited (Received)	(5)	115
Additional Collateral that could be Required	864	945
Liquidity Available under PSEG's and Power's Credit Facilities to Post Collateral	3,215	3,495
Other Letters of Credit	51	$ 45
755 MW Gas-Fired Combined Cycle Generating Station [Member]
Other Commitments [Line Items]
Face Value of Outstanding Guarantees	21
PennEast Natural Gas Pipeline [Member]
Other Commitments [Line Items]
Face Value of Outstanding Guarantees	$ 106