Shareholders' Equity (Other Comprehensive Income (Loss)) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stockholders' Equity Note [Abstract]
Gain on cash flow hedges, gross amount	$ 3	$ (23)	$ (81)
Gain on cash flow hedges, provision (benefit) for income tax	0	3	22
Gain on cash flow hedges, net amount	3	(20)	(59)
Unrealized gains on securities, gross amount	12	6	(1)
Unrealized gains on securities, provision (benefit) for income tax	(4)	(2)	0
Unrealized gains on securities, net amount	8	4	(1)
Foreign currency translation adjustments, gross amount	(118)	141	(89)
Foreign currency translation adjustments, provision (benefit) for income tax	0	130	18
Foreign currency translation adjustments, net amount	(118)	271	(71)
Change in retirement plans' funded status, gross amount	2,595	(1,149)	(1,129)
Change in retirement plans' funded status, provision (benefit) for income tax	(898)	431	384
Change in retirement plans' funded status, net amount	1,697	(718)	(745)
Other comprehensive loss, gross amount	2,492	(1,025)	(1,300)
Other comprehensive loss, provision (benefit) for income tax	(902)	562	424
Other comprehensive loss, net amount	$ 1,590	$ (463)	$ (876)