Commitments And Contingent Liabilities (Guaranteed Obligations) (Detail) (Power [Member], USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Power [Member]
Face Value of Outstanding Guarantees	$ 1,811	$ 1,814
Exposure under Current Guarantees	244	273
Letters of Credit Margin Posted	140	159
Letters of Credit Margin Received	91	40
Counterparty Cash Margin Deposited	0	0
Counterparty Cash Margin Received	(9)	(13)
Net Broker Balance Deposited (Received)	97	115
Additional Collateral that could be Required	881	945
Liquidity Available under PSEG's and Power's Credit Facilities to Post Collateral	3,514	3,495
Other Letters of Credit	$ 45	$ 45