Accumulated Other Comprehensive Income (Loss) (Income (Expense) Effect of Reclassifications) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Affected Line Item on the Statements of Income [Line Items]
Depreciation	$ (216)	$ (230)	$ (432)	$ (455)
Other Income (Expense) - net	(102)	(74)	(14)	(103)
Interest Expense	(215)	(208)	(424)	(424)
Total Pre-tax	321	396	1,090	952
Income Taxes	(71)	(166)	(288)	(333)
Total After-Tax	250	230	802	619
Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income [Line Items]
Total After-Tax	(64)	(23)	(83)	(69)
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	2	2	4	4
Total Pre-tax	2	2	4	4
Income Taxes	(1)	(1)	(2)	(2)
Total After-Tax	1	1	2	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	(51)	10	(30)	(13)
Income Taxes	24	(5)	20	(1)
Total After-Tax	(27)	5	(10)	(14)
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	(3)	(4)	(7)	(7)
Discontinued operations	(77)	0	(77)	0
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	15	0	32	(29)
Interest Expense	1	1	2	1
Qualifying Derivatives [Member] | Energy Commodities [Member] | Amounts Reclassified From Accumulated Other Comprehensive Income [Member]
Affected Line Item on the Statements of Income [Line Items]
Discontinued operations	13	13	20	22
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	(50)	(38)	(101)	(76)
Income Taxes	12	9	25	19
Total After-Tax	(38)	(29)	(76)	(57)
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	0	(2)	0	(4)
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	(50)	(36)	(101)	(72)
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	2	0
Total Pre-tax	0	0	2	0
Income Taxes	0	0	(1)	0
Total After-Tax	$ 0	$ 0	$ 1	$ 0