Commitments And Contingent Liabilities (Leveraged Lease Investments) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Jun. 30, 2012	Dec. 31, 2012
PSEG [Member]
Site Contingency [Line Items]
Unrecognized tax benefit potential increase on settlement with IRS		$ (175)
Financial statement tax reserves		246
Unrecognized tax benefit decrease on settlement with IRS		71
Amount deposited with IRS to defray potential interest costs		320
Tax and interest deficiency	4
PSEG To IRS [Member]
Site Contingency [Line Items]
Estimate of tax interest potentially payable in current year from 2004 through 2006 tax years high estimate		620
IRS To PSEG [Member]
Site Contingency [Line Items]
Estimate of tax interest potentially payable in current year from 2007 through two 2010 years high estimate		676
IRS [Member]
Site Contingency [Line Items]
Claims payments		620
Refund of claims		676
Tax deduction for the accrued deficiency interest		$ 100