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, 2020	Dec. 31, 2019
Schedule of Financial Receivables [Line Items]
Lease Receivables (net of Non-Recourse Debt)	$ 470	$ 498
Standard & Poor's, AA Rating [Member]
Schedule of Financial Receivables [Line Items]
Lease Receivables (net of Non-Recourse Debt)	9
Standard & Poor's, A- Rating [Member]
Schedule of Financial Receivables [Line Items]
Lease Receivables (net of Non-Recourse Debt)	54
Standard & Poor's, BBB plus - BBB - Rating [Member]
Schedule of Financial Receivables [Line Items]
Lease Receivables (net of Non-Recourse Debt)	237
Standard & Poor's, BB Rating [Member]
Schedule of Financial Receivables [Line Items]
Lease Receivables (net of Non-Recourse Debt)	132
Not Rated [Member]
Schedule of Financial Receivables [Line Items]
Lease Receivables (net of Non-Recourse Debt)	$ 38