Shareholders' Equity (Accumulated other comprehensive income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (8,883)	[1]	$ (17,041)	[1]	$ (9,894)	[1]	$ (17,416)	[1]
OCI before reclassifications	60	[1]	(127)	[1]	688	[1]	(144)	[1]
Amounts reclassified from AOCI	164	[1]	374	[1]	547	[1]	766	[1]
Net current period Other comprehensive income/(loss)	224	[1]	247	[1]	1,235	[1]	622	[1]
Ending Balance	(8,659)	[1]	(16,794)	[1]	(8,659)	[1]	(16,794)	[1]
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net (Gain) Loss, Net of Tax	164		377		333		755
Amortization of actuarial losses included in net periodic pension cost, tax	(91)		(216)		(185)		(431)
Settlements, curtailments and amortization of actuarial gains/losses included in net periodic pension cost, net of tax	163				535
Settlements, curtailments and amortization of actuarial gains/losses included in net periodic pension cost, tax	(91)				(298)
Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	167		191		150		214
OCI before reclassifications	21		(65)		38		(88)
Amounts reclassified from AOCI
Net current period Other comprehensive income/(loss)	21		(65)		38		(88)
Ending Balance	188		126		188		126
Unrealized Gains and Losses on Certain Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(6)		(8)		(8)		(8)
OCI before reclassifications	1				3
Amounts reclassified from AOCI
Net current period Other comprehensive income/(loss)	1				3
Ending Balance	(5)		(8)		(5)		(8)
Unrealized Gains and Losses on Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(12)		62		(6)		86
OCI before reclassifications	36		(63)		25		(89)
Amounts reclassified from AOCI	(4)		(5)		1		(3)
Net current period Other comprehensive income/(loss)	32		(68)		26		(92)
Ending Balance	20		(6)		20		(6)
Defined Benefit Pension Plans and Other Postretirement Benefits [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(9,032)		(17,286)		(10,030)		(17,708)
OCI before reclassifications	2		1		622		33
Amounts reclassified from AOCI	168	[2]	379	[2]	546	[2]	769	[2]
Net current period Other comprehensive income/(loss)	170		380		1,168		802
Ending Balance	$ (8,862)		$ (16,906)		$ (8,862)		$ (16,906)

[1] Net of tax.

[2] Primarily relates to amortization of actuarial gains/losses for the six and three months ended June 30, 2013 totaling $755 and $377 (net of tax of $(431) and $(216)) and to settlements, curtailments and amortization of actuarial gains/losses for the six and three months ended June 30, 2014 totaling $535 and $163 (net of tax of ($298) and $(91)). These are included in the net periodic pension cost of which a portion is allocated to production as inventoried costs.