Commitments And Contingent Liabilities (Guaranteed Obligations) (Detail) - Power [Member] - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Loss Contingencies [Line Items]
Face Value of Outstanding Guarantees	$ 1,733	$ 1,814
Exposure under Current Guarantees	184	273
Letters of Credit Margin Posted	178	159
Letters of Credit Margin Received	80	40
Counterparty Cash Margin Deposited	0	0
Counterparty Cash Margin Received	(44)	(13)
Net Broker Balance Deposited (Received)	4	115
Additional Collateral that could be Required	796	945
Liquidity Available under PSEG’s and Power’s Credit Facilities to Post Collateral	3,375	3,495
Other Letters of Credit	47	$ 45
PennEast Natural Gas Pipeline [Member]
Loss Contingencies [Line Items]
Face Value of Outstanding Guarantees	106
755 MW Gas-Fired Combined Cycle Generating Station [Member]
Loss Contingencies [Line Items]
Face Value of Outstanding Guarantees	$ 21