Reclassifications out of Accumulated Other Comprehensive Income Reclassifications out of Accumulated Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Provision for income taxes	$ (787)	$ (1,279)	$ (2,890)	$ (3,231)
Income before income taxes	1,356	1,729	4,268	4,491
Other Expenses	(126)	(112)	(323)	(311)
Total reclassification for the period	569	450	1,378	1,260
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Actuarial loss	(9)		(38)
Net settlement loss	(15)		(32)
Provision for income taxes	9		26
Income before income taxes	(15)		(44)
Other Expenses	0		(1)
Total reclassification for the period	$ (15)		$ (45)