Reclassifications out of Accumulated Other Comprehensive Income Reclassifications out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Provision for income taxes	$ 396	$ (149)	$ 546	$ (500)
Other insignificant, net of tax	(93)	(99)	(281)	(303)
Total reclassifications	(749)	431	(1,411)	2,120
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amortization of actuarial loss	(6)	(7)	(20)	(23)
Net settlement loss	(18)	(22)	(99)	(93)
Net curtailment gain (loss)	(4)	0	(1)	0
Income before income taxes	(28)	(29)	(120)	(116)
Provision for income taxes	10	10	44	38
Other insignificant, net of tax	0	0	0	(1)
Total reclassifications	$ (18)	$ (19)	$ (76)	$ (79)