Accumulated Other Comprehensive Income (Loss) - Income (Expense) Effect of Reclassifications (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Affected Line Item on the Statements of Income [Line Items]
Interest Expense	$ (224)	$ (215)	$ (448)	$ (424)
Other Income (Expense) - net	174	(102)	235	(14)
Total Pre-tax	675	321	1,335	1,090
Income Taxes	(192)	(71)	(371)	(288)
Total After-tax	483	250	964	802
Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income [Line Items]
Total After-tax	(117)	(64)	(70)	(83)
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	0	4
Total Pre-tax	0	2	0	4
Income Taxes	0	(1)	0	(2)
Total After-tax	0	1	0	2
Qualifying Derivatives [Member] | Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income [Line Items]
Total Pre-tax	(106)	(51)	(9)	(30)
Income Taxes	21	24	2	20
Total After-tax	(85)	(27)	(7)	(10)
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	(2)	(3)	(3)	(7)
Discontinued operations	0	(77)	0	(77)
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]
Interest Expense	(1)	1	0	2
Other Income (Expense) - net	(103)	15	(6)	32
Qualifying Derivatives [Member] | Commodity Contracts [Member] | Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income [Line Items]
Discontinued operations	0	13	0	20
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	1	0	1	2
Total Pre-tax	1	0	1	2
Income Taxes	0	0	0	(1)
Total After-tax	1	0	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	(41)	(50)	(81)	(101)
Income Taxes	8	12	17	25
Total After-tax	(33)	(38)	(64)	(76)
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)	0	(1)	0
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)	$ (50)	$ (80)	$ (101)