Financing Receivables (Schedule Of Lease Receivables, Net Of Nonrecourse Debt, Associated With Leveraged Lease Portfolio Based On Counterparty Credit Rating) (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Guarantor Obligations [Line Items]
Lease Receivables, Net of Non-Recourse Debt	$ 1,256	$ 1,316
Energy Holdings [Member]
Guarantor Obligations [Line Items]
Lease Receivables, Net of Non-Recourse Debt	721	763
Energy Holdings [Member] | Counterparties' Credit Rating (S&P), AA [Member]
Guarantor Obligations [Line Items]
Lease Receivables, Net of Non-Recourse Debt	21	21
Energy Holdings [Member] | Counterparties' Credit Rating (S&P), A+ [Member]
Guarantor Obligations [Line Items]
Lease Receivables, Net of Non-Recourse Debt	73	110
Energy Holdings [Member] | Counterparties' Credit Rating (S&P), BBB+ - BBB- [Member]
Guarantor Obligations [Line Items]
Lease Receivables, Net of Non-Recourse Debt	316	316
Energy Holdings [Member] | Counterparties' Credit Rating (S&P), B- [Member]
Guarantor Obligations [Line Items]
Lease Receivables, Net of Non-Recourse Debt	166	299
Energy Holdings [Member] | Counterparties' Credit Rating (S&P), CCC+ [Member]
Guarantor Obligations [Line Items]
Lease Receivables, Net of Non-Recourse Debt	134	0
Energy Holdings [Member] | Counterparties' Credit Rating (S&P) Not Rated [Member]
Guarantor Obligations [Line Items]
Lease Receivables, Net of Non-Recourse Debt	$ 11	$ 17