Accumulated Other Comprehensive Income (Loss) - Income (Expense) Effect of Reclassifications (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Affected Line Item on the Statements of Income [Line Items]
Interest Expense	$ (249)	$ (259)	$ (750)	$ (746)
Other Income (Expense) - net	52	126	253	309
Income Taxes	(209)	(118)	(423)	(328)
Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income [Line Items]
Total After-tax	(100)	2	(173)	(38)
Qualifying Derivatives [Member] | Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income [Line Items]
Total Pre-tax	(60)	25	(33)	28
Income Taxes	12	(3)	8	(3)
Total After-tax	(48)	22	(25)	25
Qualifying Derivatives [Member] | Interest Rate Swaps [Member] | Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income [Line Items]
Interest Expense	(4)	(2)	(9)	(6)
Qualifying Derivatives [Member] | Cross Currency Swaps [Member] | Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income [Line Items]
Other Income (Expense) - net	(56)	27	(24)	34
Defined Benefit Plans [Member] | Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income [Line Items]
Total Pre-tax	(65)	(26)	(184)	(80)
Income Taxes	13	6	36	17
Total After-tax	(52)	(20)	(148)	(63)
Defined Benefit Plans [Member] | Prior Service Costs [Member] | Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income [Line Items]
Total Pre-tax	(1)	(1)	(3)	(2)
Defined Benefit Plans [Member] | Net Actuarial Loss [Member] | Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income [Line Items]
Total Pre-tax	$ (64)	$ (25)	$ (181)	$ (78)