Commitments And Contingent Liabilities (Capital Expenditures) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Long-term Purchase Commitment [Line Items]
Capital Expenditures			$ 6,100
Total expenditures to date	(724)	(687)
Energy Holdings-Solar [Member]
Long-term Purchase Commitment [Line Items]
Guarantee payment of obligations	41
Power [Member]
Long-term Purchase Commitment [Line Items]
Total expenditures to date	(143)	(237)
Payments for Nuclear Fuel	(41)
Power [Member] | General Plant Assets [Member]
Long-term Purchase Commitment [Line Items]
Total expenditures to date	(102)
PSE And G [Member]
Long-term Purchase Commitment [Line Items]
Total expenditures to date	(572)	(435)
Payments for Removal Costs	24
Total Capital Expenditures	(583)
Solar Loan Investment [Member] | PSE And G [Member]
Long-term Purchase Commitment [Line Items]
Total expenditures to date	(11)
Fiscal Year 2013 [Member]
Long-term Purchase Commitment [Line Items]
Capital Expenditures	2,535
Fiscal Year 2013 [Member] | Power [Member]
Long-term Purchase Commitment [Line Items]
Capital Expenditures	400
Fiscal Year 2013 [Member] | PSE And G [Member]
Long-term Purchase Commitment [Line Items]
Capital Expenditures	2,040
Fiscal Year 2013 [Member] | Other Entity [Member]
Long-term Purchase Commitment [Line Items]
Capital Expenditures	95
Fiscal Year 2014 [Member]
Long-term Purchase Commitment [Line Items]
Capital Expenditures	2,085
Fiscal Year 2014 [Member] | Power [Member]
Long-term Purchase Commitment [Line Items]
Capital Expenditures	365
Fiscal Year 2014 [Member] | PSE And G [Member]
Long-term Purchase Commitment [Line Items]
Capital Expenditures	1,680
Fiscal Year 2014 [Member] | Other Entity [Member]
Long-term Purchase Commitment [Line Items]
Capital Expenditures	40
Fiscal Year 2015 [Member]
Long-term Purchase Commitment [Line Items]
Capital Expenditures	1,515
Fiscal Year 2015 [Member] | Power [Member]
Long-term Purchase Commitment [Line Items]
Capital Expenditures	305
Fiscal Year 2015 [Member] | PSE And G [Member]
Long-term Purchase Commitment [Line Items]
Capital Expenditures	1,180
Fiscal Year 2015 [Member] | Other Entity [Member]
Long-term Purchase Commitment [Line Items]
Capital Expenditures	$ 30