Changes in Accumulated Other Comprehensive Losses (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015		Jun. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	[1]			$ (4,859)
Components of Other Comprehensive Income (Loss):
Before Reclassifications	[1]			(16)
Reclassifications	[1],[2]			224
Other Comprehensive Gain, Net of Tax		$ 129	$ 37	208	[1]	$ 82
Balance at end of period	[1]	(4,651)		(4,651)
Income tax expense		755	$ 3,337	1,060		$ 6,744
Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	[1]			(96)
Components of Other Comprehensive Income (Loss):
Before Reclassifications	[1]			(19)
Reclassifications	[1],[2]			0
Other Comprehensive Gain, Net of Tax	[1]			(19)
Balance at end of period	[1]	(115)		(115)
Unrealized Holding Gains (Losses) on Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	[1]			(8)
Components of Other Comprehensive Income (Loss):
Before Reclassifications	[1]			(6)
Reclassifications	[1],[2]			0
Other Comprehensive Gain, Net of Tax	[1]			(6)
Balance at end of period	[1]	(14)		(14)
Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	[1]			(2)
Components of Other Comprehensive Income (Loss):
Before Reclassifications	[1]			0
Reclassifications	[1],[2]			0
Other Comprehensive Gain, Net of Tax	[1]			0
Balance at end of period	[1]	(2)		(2)
Defined Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period	[1]			(4,753)
Components of Other Comprehensive Income (Loss):
Before Reclassifications	[1]			9
Reclassifications	[1],[2]			224
Other Comprehensive Gain, Net of Tax	[1]			233
Balance at end of period	[1]	$ (4,520)		(4,520)
Defined Benefit Plans [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Components of Other Comprehensive Income (Loss):
Employee benefits reclassification component, included in employee benefit costs				358
Income tax expense				$ 134

[1] All amounts are net of tax.

[2] Refer to Note 10, Employee Benefits for reclassified components totaling $358 million that are included in employee benefit costs for the six months ending June 30, 2015. Related income taxes for the same period, totaling $134 million, are reflected in Income Tax Expense on the Consolidated Statement of Income. All other reclassified amounts were insignificant.