Commitments And Contingent Liabilities (Leveraged Lease Investments) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Jun. 30, 2012	Mar. 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		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]
Tax deduction for the accrued deficiency interest	$ 100