Leases (Schedule Of Future Minimum Commitments) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Operating
Due next twelve months	$ 698	$ 709
Due year two	590	619
Due year three	402	553
Due year four	287	389
Due year five	222	295
Due after year five	634	858
Gross lease payments	2,833	3,423
Less: imputed interest	354
Total operating lease liabilities	2,479
Finance
Due next twelve months	96	70
Due year two	87	71
Due year three	95	66
Due year four	98	75
Due year five	84	82
Due after year five	527	586
Gross lease payments	987	950
Less: imputed interest	289	301
Finance lease obligations	$ 698	$ 649