Shareholders' Equity (Accumulated other comprehensive income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended			3 Months Ended	9 Months Ended				3 Months Ended	9 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012	Sep. 30, 2013 Currency Translation Adjustments [Member]	Sep. 30, 2013 Currency Translation Adjustments [Member]	Sep. 30, 2013 Unrealized Gains and Losses on Certain Investments	Jun. 30, 2013 Unrealized Gains and Losses on Certain Investments	Dec. 31, 2012 Unrealized Gains and Losses on Certain Investments	Sep. 30, 2013 Unrealized Gains and Losses on Derivative Instruments	Sep. 30, 2013 Unrealized Gains and Losses on Derivative Instruments	Sep. 30, 2013 Defined Benefit Pension Plans and Other Postretirement Benefits		Sep. 30, 2013 Defined Benefit Pension Plans and Other Postretirement Benefits
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (16,794)	[1]		$ (17,416)	[1]		$ 126	$ 214	$ (8)	$ (8)	$ (8)	$ (6)	$ 86	$ (16,906)		$ (17,708)
OCI before reclassifications	179	[1]		35	[1]		42	(46)				35	(54)	102		135
Amounts reclassified from AOCI	428	[1]		1,194	[1]							(10)	(13)	438	[2]	1,207	[2]
Net current period OCI	607	[1]		1,229	[1]		42	(46)				25	(67)	540		1,342
Balance September 30, 2013	(16,187)	[1]		(16,187)	[1]		168	168	(8)	(8)	(8)	19	19	(16,366)		(16,366)
Other Comprehensive Income (Loss), Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost, Net of Tax	(380)		(326)	(1,135)		(979)
Amortization of actuarial losses included in net periodic pension cost, tax	$ 213		$ (188)	$ 644		$ (563)

[1] Net of tax.

[2] Primarily relates to amortization of actuarial gains/losses for the nine and three months ended September 30, 2013 totaling $1,135 and $380 (net of tax of $644 and $213) which is included in the net periodic pension cost of which a portion is allocated to production as inventoried costs.