Long-Term Investments (Schedule Of Net Investment In Leveraged Leases) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of Investments [Line Items]
Maximum U.S. Corporate Income Tax Rate		35.00%
Lease Receivables (net of Non-Recourse Debt)		$ 546	$ 629
Estimated Residual Value of Leased Assets		326	346
Total Investment in Rental Receivables		872	975
Unearned and Deferred Income		(307)	(326)
Gross Investment in Leases		565	649
Deferred Tax Liabilities		(480)	(674)
Net Investments in Leases		$ 85	$ (25)
Subsequent Event [Member]
Schedule of Investments [Line Items]
Maximum U.S. Corporate Income Tax Rate	21.00%