Shareholders' Equity (Accumulated other comprehensive income) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Balance	$ (17,416)	[1]	$ (16,500)	[1]	$ (13,758)	[1]
OCI before reclassifications	5,954	[1]	(2,248)	[1]	(3,771)	[1]
Amounts reclassified from AOCI	1,568	[1]	1,332	[1]	1,029	[1]
Net current period OCI	7,522	[1]	(916)	[1]	(2,742)	[1]
Balance	(9,894)	[1]	(17,416)	[1]	(16,500)	[1]
Defined benefit pension plans & other postretirement benefits:
Amortization of actuarial losses included in net periodic pension cost, net of tax	1,516		1,304		909
Amortization of actuarial losses included in net periodic pension cost, tax	(849)		(752)		(523)
Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Balance	214		197		232
OCI before reclassifications	(64)		17		(35)
Amounts reclassified from AOCI
Net current period OCI	(64)		17		(35)
Balance	150		214		197
Unrealized Gains and Losses on Certain Investments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Balance					(6)
OCI before reclassifications					(2)
Net current period OCI					(2)
Balance	(8)		(8)		(8)
Unrealized Gains and Losses on Derivative Instruments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Balance	86		66		95
OCI before reclassifications	(75)		25		(13)
Amounts reclassified from AOCI	(17)		(5)		(16)
Net current period OCI	(92)		20		(29)
Balance	(6)		86		66
Defined Benefit Pension Plans and Other Postretirement Benefits
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Balance	(17,708)		(16,755)		(14,079)
OCI before reclassifications	6,093		(2,290)		(3,721)
Amounts reclassified from AOCI	1,585	[2]	1,337	[2]	1,045	[2]
Net current period OCI	7,678		(953)		(2,676)
Balance	$ (10,030)		$ (17,708)		$ (16,755)

[1] Net of tax.

[2] Primarily relates to amortization of actuarial gains/losses for the years ended December 31, 2013 2012 and 2011 totaling $1,516, $1,304 and $909 (net of tax of ($849), ($752) and ($523)) which is included in the net periodic pension cost of which a portion is allocated to production as inventoried costs. See Note 14.