Litigation And Other Contingencies (Schedule Of Guarantees) (Details) $ in Millions	Sep. 30, 2020 USD ($)
Litigation And Other Contingencies [Line Items]
Guarantees	$ 6,584
Equity Company Obligations [Member]
Litigation And Other Contingencies [Line Items]
Guarantees	1,658
Other Third Party Obligations [Member]
Litigation And Other Contingencies [Line Items]
Guarantees	4,926
Debt Related Guarantees [Member]
Litigation And Other Contingencies [Line Items]
Guarantees	1,088
Debt Related Guarantees [Member] | Equity Company Obligations [Member]
Litigation And Other Contingencies [Line Items]
Guarantees	968
Debt Related Guarantees [Member] | Other Third Party Obligations [Member]
Litigation And Other Contingencies [Line Items]
Guarantees	120
Other Guarantees [Member]
Litigation And Other Contingencies [Line Items]
Guarantees	5,496
Other Guarantees [Member] | Equity Company Obligations [Member]
Litigation And Other Contingencies [Line Items]
Guarantees	690
Other Guarantees [Member] | Other Third Party Obligations [Member]
Litigation And Other Contingencies [Line Items]
Guarantees	$ 4,806