Commitments And Contingent Liabilities (Guaranteed Obligations) (Detail) - Power [Member] - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Loss Contingencies [Line Items]
Face Value of Outstanding Guarantees	$ 1,775	$ 1,814
Exposure under Current Guarantees	196	273
Letters of Credit Margin Posted	161	159
Letters of Credit Margin Received	74	40
Counterparty Cash Margin Deposited	0	0
Counterparty Cash Margin Received	(9)	(13)
Net Broker Balance Deposited (Received)	42	115
Additional Collateral that could be Required	907	945
Liquidity Available under PSEG’s and Power’s Credit Facilities to Post Collateral	3,494	3,495
Other Letters of Credit	45	$ 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	$ 23