Debt (Schedule Of Debt) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Debt	$ 26,394
Unamortized discount and deferred issuance costs	(1,194)	$ (817)
Total debt	25,200	22,391
Less: current portion	(1,257)	(1,466)
Total long-term debt	23,943	20,925
Bank Note [Member]
Debt Instrument [Line Items]
Debt	$ 24,008	20,627
Debt due through	Sep. 15, 2067
Bank Note [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Stated percentage rate	1.80%
Bank Note [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Stated percentage rate	7.10%
Pass-Through Trust Certificate [Member]
Debt Instrument [Line Items]
Debt	$ 923	969
Debt due through	Jan. 02, 2031
Pass-Through Trust Certificate [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Stated percentage rate	2.60%
Pass-Through Trust Certificate [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Stated percentage rate	6.20%
Finance leases [Member]
Debt Instrument [Line Items]
Debt	$ 605	754
Debt due through	Dec. 10, 2028
Finance leases [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Stated percentage rate	3.10%
Finance leases [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Stated percentage rate	8.00%
Receivables Securitization (Note 11) [Member]
Debt Instrument [Line Items]
Debt	$ 400	400
Term loans - floating rate [Member]
Debt Instrument [Line Items]
Debt	$ 250	250
Debt due through	Oct. 29, 2020
Commercial Paper [Member]
Debt Instrument [Line Items]
Debt	$ 200	200
Debt due through	Jan. 09, 2020
Commercial Paper [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Stated percentage rate	1.80%
Commercial Paper [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Stated percentage rate	2.00%
Medium-term notes [Member]
Debt Instrument [Line Items]
Debt	$ 8	$ 8
Debt due through	Apr. 15, 2020
Medium-term notes [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Stated percentage rate	9.30%
Medium-term notes [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Stated percentage rate	10.00%

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of long-term debt and lease obligation, classified as noncurrent.

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