Accumulated Other Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Loss, Pension and Other Benefit Liabilities	$ (5,275)	$ (8,136)	$ (5,323)	$ (8,304)
Accumulated Other Comprehensive Income (Loss), Derivative Contracts	197	(169)	219	(263)
Accumulated Other Comprehensive Loss, Investments, Net of Tax	(22)	(19)	(26)	(10)
Accumulated other comprehensive loss	(5,100)	(8,324)	(5,130)	(8,577)
Changes in value, Pension and Other Benefit Liabilities, Net of Tax	0	0
Changes in value, Derivative contracts, Net of Tax	33	194
Changes in value, Investments, Net of Tax	4	(9)
Changes in value, Accumulated Other Comprehensive Loss, Net of Tax	37	185
Reclassification into earnings, Pension and Other Benefit Liabilities, Net of Tax	48	168
Reclassification into earnings, Derivative contracts, Net of Tax	(55)	(100)
Reclassification into earnings, Investments, Net of Tax	0	0
Reclassification into earnings, Accumulated Other Comprehensive Loss, Net of Tax	$ (7)	$ 68