Related-Party Transactions (Schedule Of Related Party Transactions, Receivables) (Detail) (Power [Member], USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Power [Member]
Receivables from PSE&G through BGS and BGSS Contracts	$ 223	$ 238
Receivables from PSE&G Related to Gas Supply Hedges for BGSS	(23)	27
Receivable from (Payable to) Services	(26)	(31)
Tax Receivable from (Payable to) PSEG	(6)	111
Receivable from (Payable to) PSEG	2	(5)
Accounts Receivable-Affiliated Companies, net	170	340
Short-Term Loan to Affiliate (Demand Note to PSEG)	748	574
Working Capital Advances to Services	17	17
Long-Term Accrued Taxes Receivable (Payable)	$ (38)	$ (50)