Changes in Accumulated Other Comprehensive Losses (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013	Sep. 30, 2014		Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period				$ (3,579)	[1]
Components of Other Comprehensive Income (Loss):
Before Reclassifications				(80)	[1]
Reclassifications				221	[1],[2]
Other Comprehensive Gain, Net of Tax	59		81	141	[1]	372
Balance at end of period	(3,438)	[1]		(3,438)	[1]
Income tax expense	3,236		3,839	9,980		11,068
Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period				(23)	[1]
Components of Other Comprehensive Income (Loss):
Before Reclassifications				(49)	[1]
Reclassifications				0	[1],[2]
Other Comprehensive Gain, Net of Tax				(49)	[1]
Balance at end of period	(72)	[1]		(72)	[1]
Unrealized Holding Gains (Losses) on Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period				(6)	[1]
Components of Other Comprehensive Income (Loss):
Before Reclassifications				4	[1]
Reclassifications				0	[1],[2]
Other Comprehensive Gain, Net of Tax				4	[1]
Balance at end of period	(2)	[1]		(2)	[1]
Derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period				52	[1]
Components of Other Comprehensive Income (Loss):
Before Reclassifications				(43)	[1]
Reclassifications				(11)	[1],[2]
Other Comprehensive Gain, Net of Tax				(54)	[1]
Balance at end of period	(2)	[1]		(2)	[1]
Defined Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance at beginning of period				(3,602)	[1]
Components of Other Comprehensive Income (Loss):
Before Reclassifications				8	[1]
Reclassifications				232	[1],[2]
Other Comprehensive Gain, Net of Tax				240	[1]
Balance at end of period	(3,362)	[1]		(3,362)	[1]
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				369
Income tax expense				$ 137

[1] All amounts are net of tax.

[2] Refer to Note 9, Employee Benefits for reclassified components totaling $369 million that are included in employee benefit costs for the nine months ending September 30, 2014. Related income taxes for the same period, totaling $137 million, are reflected in Income Tax Expense on the Consolidated Statement of Income. All other reclassified amounts were insignificant.