Financing Receivables (Schedule Of Lease Receivables, Net Of Nonrecourse Debt, Associated With Leveraged Lease Portfolio Based On Counterparty Credit Rating) (Detail) - Energy Holdings [Member] - USD ($) $ in Millions |
Mar. 31, 2018 |
Dec. 31, 2017 |
|---|---|---|
| Schedule of Financial Receivables [Line Items] | ||
| Lease Receivables (net of Non-Recourse Debt) | $ 545 | $ 546 |
| Standard & Poor's, AA Rating [Member] | ||
| Schedule of Financial Receivables [Line Items] | ||
| Lease Receivables (net of Non-Recourse Debt) | 14 | |
| Standard & Poor's, BBB plus - BBB - Rating [Member] | ||
| Schedule of Financial Receivables [Line Items] | ||
| Lease Receivables (net of Non-Recourse Debt) | 316 | |
| Standard & Poor's, BB- Rating [Member] | ||
| Schedule of Financial Receivables [Line Items] | ||
| Lease Receivables (net of Non-Recourse Debt) | 133 | |
| Standard & Poor's, CCC minus Rating [Member] | ||
| Schedule of Financial Receivables [Line Items] | ||
| Lease Receivables (net of Non-Recourse Debt) | $ 82 |