Commitments And Contingent Liabilities (Face Value Of Outstanding Guarantees, Current Exposure And Margin Positions) (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 mi	Dec. 31, 2013	Dec. 31, 2012
Other Commitments [Line Items]
Number Of Miles Pertaining To Passaic River Tidal Reach Required To Be Studied By Epa	8
Operation and Maintenance	$ 3,150	$ 2,887	$ 2,632
Estimate of Total Costs required to restore damaged facilities	564
Face Value of Outstanding Guarantees	106
Power [Member]
Other Commitments [Line Items]
Operation and Maintenance	1,186	1,224	1,127
Estimate of Total Costs required to restore damaged facilities	476
Face Value of Outstanding Guarantees	1,814	1,639
Exposure under Current Guarantees	273	246
Letters of Credit Margin Posted	159	132
Letters of Credit Margin Received	40	25
Counterparty Cash Margin Deposited	0	0
Counterparty Cash Margin Received	(13)	0
Net Broker Balance Deposited (Received)	115	80
Additional Collateral that could be Required	945	691
Liquidity Available under PSEG's and Power's Credit Facilities to Post Collateral	3,495	3,522
Other Letters of Credit	$ 45	$ 45