Accumulated Other Comprehensive Income (Loss) - Income (Expense) Effect of Reclassifications (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Affected Line Item on the Statements of Income [Line Items]
Other Income (Expense) - net	$ 49	$ 75	$ 284	$ 61
Interest Expense	(223)	(221)	(671)	(645)
Total Pre-tax	612	540	1,947	1,630
Income Taxes	(139)	(144)	(510)	(432)
Total After-tax	473	396	1,437	1,198
Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income [Line Items]
Total After-tax	38	(45)	(32)	(128)
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	0	0	4
Total Pre-tax	0	0	0	4
Income Taxes	0	0	0	(2)
Total After-tax	0	0	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	86	(13)	77	(43)
Income Taxes	(17)	3	(15)	23
Total After-tax	69	(10)	62	(20)
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)	(2)	(5)	(9)
Discontinued operations	0	0	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]
Other Income (Expense) - net	86	(10)	80	22
Interest Expense	2	(1)	2	1
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	0	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	0	0	1	2
Total Pre-tax	0	0	1	2
Income Taxes	0	0	0	(1)
Total After-tax	0	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	(42)	(45)	(123)	(146)
Income Taxes	11	10	28	35
Total After-tax	(31)	(35)	(95)	(111)
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	(2)	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	$ (41)	$ (45)	$ (121)	$ (146)