Accumulated Other Comprehensive Income (Loss) (Income (Expense) Effect of Reclassifications) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Affected Line Item on the Statements of Income [Line Items]
Depreciation	$ (229)	$ (216)
Other Income (Expense) - net	61	88
Interest Expense	(224)	(209)
Total Pre-tax	660	769
Income tax benefit	(179)	(217)
Total After-Tax	481	552
Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income [Line Items]
Total After-Tax	47	(19)
Commodity Contracts [Member]
Affected Line Item on the Statements of Income [Line Items]
Discontinued operations	0	7
Available For Sale Securities [Member] | Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income [Line Items]
Other Income (Expense) - net	0	2
Total Pre-tax	0	2
Income tax benefit	0	(1)
Total After-Tax	0	1
Qualifying Derivatives [Member] | Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income [Line Items]
Total Pre-tax	97	21
Income tax benefit	(19)	(4)
Total After-Tax	78	17
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	(1)	(4)
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	97	17
Interest Expense	1	1
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	(40)	(51)
Income tax benefit	9	13
Total After-Tax	(31)	(38)
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	(40)	(51)
Equity Investees Accumulated Other Comprehensive Income [Member] | Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income [Line Items]
Other Income (Expense) - net	0	2
Total Pre-tax	0	2
Income tax benefit	0	(1)
Total After-Tax	$ 0	$ 1