Retirement Benefits - Status (Details) (USD $)	3 Months Ended			12 Months Ended			24 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013
Change in Plan Assets
Settlements					$ 3,000,000,000	$ 1,200,000,000	$ 4,200,000,000
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year [Abstract]
Prior service cost/(credit)				(5,000,000)
(Gains)/Losses				1,377,000,000
Defined Benefit Plan, Assets, Target Allocations [Abstract]
Defined Benefit Plan Percent Of Employer And Related Party Securities Included In Plan Assets Maximum				1.00%
U.S. Plans
Change in Benefit Obligation
Benefit obligation at January 1				43,182,000,000	52,125,000,000
Service cost				507,000,000	581,000,000	521,000,000
Interest cost				1,992,000,000	1,914,000,000
Amendments				0	0
Separation programs and other				(50,000,000)	(75,000,000)
Curtailments				0	0
Settlements				0	(3,089,000,000)
Plan participant contributions				26,000,000	26,000,000
Benefits paid				(3,028,000,000)	(3,120,000,000)
Foreign exchange translation				0	0
Actuarial (gain)/loss				3,692,000,000	(5,180,000,000)
Benefit obligation at December 31	43,182,000,000			46,321,000,000	43,182,000,000	52,125,000,000	43,182,000,000
Change in Plan Assets
Fair value of plan assets at January 1				41,217,000,000	42,395,000,000
Actual return on plan assets				6,542,000,000	1,539,000,000
Company contributions				130,000,000	3,535,000,000
Plan participant contributions				26,000,000	26,000,000
Benefits paid				(3,028,000,000)	(3,120,000,000)
Settlements				0	(3,089,000,000)
Foreign exchange translation				0	0
Defined Benefit Plan Other Increase Decrease Plan Assets				(43,000,000)	(69,000,000)
Fair value of plan assets at December 31	41,217,000,000			44,844,000,000	41,217,000,000	42,395,000,000	41,217,000,000
Funded status at December 31	(1,965,000,000)			(1,477,000,000)	(1,965,000,000)		(1,965,000,000)
Amounts Recognized on the Balance Sheet
Prepaid assets	443,000,000			377,000,000	443,000,000		443,000,000
Accrued liabilities	(2,408,000,000)			(1,854,000,000)	(2,408,000,000)		(2,408,000,000)
Total	(1,965,000,000)			(1,477,000,000)	(1,965,000,000)		(1,965,000,000)
Amounts Recognized in Accumulated Other Comprehensive Loss (pre-tax)
Unamortized prior service costs/(credits)	764,000,000			609,000,000	764,000,000		764,000,000
Unamortized net (gains)/losses	6,179,000,000			5,810,000,000	6,179,000,000		6,179,000,000
Total	6,943,000,000			6,419,000,000	6,943,000,000		6,943,000,000
Pension Plans in which Accumulated Benefit Obligation Exceeds Plan Assets at December 31
Accumulated benefit obligation	25,828,000,000			1,906,000,000	25,828,000,000		25,828,000,000
Fair value of plan assets	23,498,000,000			150,000,000	23,498,000,000		23,498,000,000
Accumulated Benefit Obligation at December 31	42,078,000,000			44,919,000,000	42,078,000,000		42,078,000,000
Pension Plans in which Projected Benefit Obligation Exceeds Plan Assets at December 31
Projected benefit obligation	25,906,000,000			2,004,000,000	25,906,000,000		25,906,000,000
Fair value of plan assets	23,498,000,000			150,000,000	23,498,000,000		23,498,000,000
Curtailments and Settlements [Abstract]
Defined Benefit Plan, Recognized Net (Gain)/Loss Due to Settlements	155,000,000	145,000,000	294,000,000	0	594,000,000	250,000,000	844,000,000
Business Restructuring [Abstract]
Pension-related expenses				19,000,000	10,000,000	7,000,000
Estimated Future Benefit Payments
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months				3,070,000,000
Defined Benefit Plan, Expected Future Benefit Payments, Year Two				3,030,000,000
Defined Benefit Plan, Expected Future Benefit Payments, Year Three				2,990,000,000
Defined Benefit Plan, Expected Future Benefit Payments, Year Four				2,960,000,000
Defined Benefit Plan, Expected Future Benefit Payments, Year Five				2,940,000,000
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Year Thereafter				14,440,000,000
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year [Abstract]
Prior service cost/(credit)				155,000,000
(Gains)/Losses				397,000,000
Defined Benefit Plan, Actual Return on Plan Assets [Abstract]
Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Expected Long-Term Return on Asset Rate	6.89%			6.75%	6.89%		6.89%
Defined Benefit Plan Actual Rate Of Return On Plan Assets Period				P10Y
Defined Benefit Plan Actual Ten Year Rate Of Return On Plan Assets	9.00%			9.30%	9.00%		9.00%
Non-U.S. Plans
Change in Benefit Obligation
Benefit obligation at January 1				30,851,000,000	30,702,000,000
Service cost				468,000,000	484,000,000	372,000,000
Interest cost				1,189,000,000	1,137,000,000
Amendments				11,000,000	(1,000,000)
Separation programs and other				139,000,000	141,000,000
Curtailments				0	0
Settlements				(116,000,000)	(51,000,000)
Plan participant contributions				25,000,000	25,000,000
Benefits paid				(1,423,000,000)	(1,416,000,000)
Foreign exchange translation				(2,997,000,000)	229,000,000
Actuarial (gain)/loss				5,076,000,000	(399,000,000)
Benefit obligation at December 31	30,851,000,000			33,223,000,000	30,851,000,000	30,702,000,000	30,851,000,000
Change in Plan Assets
Fair value of plan assets at January 1				23,843,000,000	21,713,000,000
Actual return on plan assets				3,656,000,000	1,689,000,000
Company contributions				1,715,000,000	1,852,000,000
Plan participant contributions				25,000,000	25,000,000
Benefits paid				(1,423,000,000)	(1,416,000,000)
Settlements				(116,000,000)	(51,000,000)
Foreign exchange translation				(2,019,000,000)	49,000,000
Defined Benefit Plan Other Increase Decrease Plan Assets				(6,000,000)	(18,000,000)
Fair value of plan assets at December 31	23,843,000,000			25,675,000,000	23,843,000,000	21,713,000,000	23,843,000,000
Funded status at December 31	(7,008,000,000)			(7,548,000,000)	(7,008,000,000)		(7,008,000,000)
Amounts Recognized on the Balance Sheet
Prepaid assets	219,000,000			696,000,000	219,000,000		219,000,000
Accrued liabilities	(7,227,000,000)			(8,244,000,000)	(7,227,000,000)		(7,227,000,000)
Total	(7,008,000,000)			(7,548,000,000)	(7,008,000,000)		(7,008,000,000)
Amounts Recognized in Accumulated Other Comprehensive Loss (pre-tax)
Unamortized prior service costs/(credits)	417,000,000			347,000,000	417,000,000		417,000,000
Unamortized net (gains)/losses	9,902,000,000			11,254,000,000	9,902,000,000		9,902,000,000
Total	10,319,000,000			11,601,000,000	10,319,000,000		10,319,000,000
Pension Plans in which Accumulated Benefit Obligation Exceeds Plan Assets at December 31
Accumulated benefit obligation	15,393,000,000			11,018,000,000	15,393,000,000		15,393,000,000
Fair value of plan assets	9,518,000,000			4,109,000,000	9,518,000,000		9,518,000,000
Accumulated Benefit Obligation at December 31	28,312,000,000			30,098,000,000	28,312,000,000		28,312,000,000
Pension Plans in which Projected Benefit Obligation Exceeds Plan Assets at December 31
Projected benefit obligation	23,653,000,000			12,874,000,000	23,653,000,000		23,653,000,000
Fair value of plan assets	16,426,000,000			4,630,000,000	16,426,000,000		16,426,000,000
Curtailments and Settlements [Abstract]
Defined Benefit Plan, Recognized Net (Gain)/Loss Due to Settlements				19,000,000	5,000,000	0
Business Restructuring [Abstract]
Pension-related expenses				81,000,000	242,000,000	162,000,000
Estimated Future Benefit Payments
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months				1,340,000,000
Defined Benefit Plan, Expected Future Benefit Payments, Year Two				1,290,000,000
Defined Benefit Plan, Expected Future Benefit Payments, Year Three				1,310,000,000
Defined Benefit Plan, Expected Future Benefit Payments, Year Four				1,330,000,000
Defined Benefit Plan, Expected Future Benefit Payments, Year Five				1,360,000,000
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Year Thereafter				7,220,000,000
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year [Abstract]
Prior service cost/(credit)				49,000,000
(Gains)/Losses				835,000,000
Defined Benefit Plan, Actual Return on Plan Assets [Abstract]
Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Expected Long-Term Return on Asset Rate	6.63%			6.11%	6.63%		6.63%
Canadian [Member]
Defined Benefit Plan, Actual Return on Plan Assets [Abstract]
Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Expected Long-Term Return on Asset Rate				5.94%
Defined Benefit Plan Actual Ten Year Rate Of Return On Plan Assets	5.80%			6.20%	5.80%		5.80%
United Kingdom
Defined Benefit Plan, Actual Return on Plan Assets [Abstract]
Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Expected Long-Term Return on Asset Rate				6.50%
Defined Benefit Plan Actual Ten Year Rate Of Return On Plan Assets	7.70%			8.30%	7.70%		7.70%
Worldwide OPEB [Member]
Change in Benefit Obligation
Benefit obligation at January 1				5,889,000,000	6,810,000,000
Service cost				54,000,000	64,000,000	67,000,000
Interest cost				269,000,000	256,000,000
Amendments				0	0
Separation programs and other				0	(11,000,000)
Curtailments				0	0
Settlements				0	0
Plan participant contributions				23,000,000	27,000,000
Benefits paid - Worldwide OPEB				(406,000,000)	(421,000,000)
Foreign exchange translation				(138,000,000)	(131,000,000)
Actuarial (gain)/loss				697,000,000	(705,000,000)
Benefit obligation at December 31	5,889,000,000			6,388,000,000	5,889,000,000	6,810,000,000	5,889,000,000
Change in Plan Assets
Fair value of plan assets at January 1				0	0
Actual return on plan assets				0	0
Company contributions				0	0
Plan participant contributions				23,000,000	27,000,000
Plan participant contributions - Worldwide OPEB				0	0
Benefits paid - Worldwide OPEB				0	0
Settlements				0	0
Foreign exchange translation				0	0
Defined Benefit Plan Other Increase Decrease Plan Assets				0	0
Fair value of plan assets at December 31	0			0	0	0	0
Funded status at December 31	(5,889,000,000)			(6,388,000,000)	(5,889,000,000)		(5,889,000,000)
Amounts Recognized on the Balance Sheet
Prepaid assets	0			0	0		0
Accrued liabilities	(5,889,000,000)			(6,388,000,000)	(5,889,000,000)		(5,889,000,000)
Total	(5,889,000,000)			(6,388,000,000)	(5,889,000,000)		(5,889,000,000)
Amounts Recognized in Accumulated Other Comprehensive Loss (pre-tax)
Unamortized prior service costs/(credits)	(959,000,000)			(710,000,000)	(959,000,000)		(959,000,000)
Unamortized net (gains)/losses	1,701,000,000			2,278,000,000	1,701,000,000		1,701,000,000
Total	742,000,000			1,568,000,000	742,000,000		742,000,000
Plan Contributions [Abstract]
Pension and Other Postretirement Benefit Contributions				1,500,000,000
Pension and Other Postretirement Benefit Contributions Unfunded Plans				400,000,000
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year				1,100,000,000
Pension And Other Postretirement Expected Benefit Contributions Unfunded Plans				400,000,000
Pension and Other Postretirement Benefit Contributions and Expected Future Employer Contributions To Funded and Unfunded Plans				1,500,000,000
Curtailments and Settlements [Abstract]
Defined Benefit Plan, Recognized Net (Gain)/Loss Due to Settlements				0	0	0
Business Restructuring [Abstract]
Pension-related expenses				0	0	2,000,000
Estimated Future Benefit Payments
Defined Benefit Plan, Expected Future Benefit Payments, Next Twelve Months				390,000,000
Defined Benefit Plan, Expected Future Benefit Payments, Year Two				390,000,000
Defined Benefit Plan, Expected Future Benefit Payments, Year Three				380,000,000
Defined Benefit Plan, Expected Future Benefit Payments, Year Four				380,000,000
Defined Benefit Plan, Expected Future Benefit Payments, Year Five				380,000,000
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Year Thereafter				1,830,000,000
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year [Abstract]
Prior service cost/(credit)				(209,000,000)
(Gains)/Losses				145,000,000
Defined Benefit Plan, Actual Return on Plan Assets [Abstract]
Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Expected Long-Term Return on Asset Rate	0.00%			0.00%	0.00%		0.00%
Fixed Income | U.S. Plans
Change in Plan Assets
Fair value of plan assets at January 1				27,854,000,000
Fair value of plan assets at December 31				33,231,000,000
Defined Benefit Plan, Assets, Target Allocations [Abstract]
Defined Benefit Plan, Target Plan Asset Allocations				80.00%
Fixed Income | Non-U.S. Plans
Change in Plan Assets
Fair value of plan assets at December 31	9,398,000,000			13,979,000,000	9,398,000,000		9,398,000,000
Alternatives
Alternative Assets [Abstract]
Lagged Valuation Adjustments Range, Low				P1M
Lagged Valuation Adjustments Range, High				P6M
Alternatives | U.S. Plans
Change in Plan Assets
Fair value of plan assets at December 31	6,014,000,000			6,166,000,000	6,014,000,000		6,014,000,000
Alternatives | Non-U.S. Plans
Change in Plan Assets
Fair value of plan assets at December 31	2,610,000,000			3,054,000,000	2,610,000,000		2,610,000,000
Growth Assets [Member] | U.S. Plans
Defined Benefit Plan, Assets, Target Allocations [Abstract]
Defined Benefit Plan, Target Plan Asset Allocations				20.00%
Real Estate Investment [Member]
Alternative Assets [Abstract]
Lagged Valuation Adjustments Amount				33,000,000	0
Hedge Funds [Member]
Alternative Assets [Abstract]
Lagged Valuation Adjustments Range, Low				P1M
Lagged Valuation Adjustments Range, High				P3M
Lagged Valuation Adjustments Amount				14,000,000	(10,000,000)
Hedge Funds [Member] | U.S. Plans
Change in Plan Assets
Fair value of plan assets at December 31	2,778,000,000			2,559,000,000	2,778,000,000		2,778,000,000
Hedge Funds [Member] | Non-U.S. Plans
Change in Plan Assets
Fair value of plan assets at December 31	1,657,000,000			1,837,000,000	1,657,000,000		1,657,000,000
Private Equity Funds [Member]
Alternative Assets [Abstract]
Lagged Valuation Adjustments Range, Low				P1M
Lagged Valuation Adjustments Range, High				P6M
Lagged Valuation Adjustments Amount				88,000,000	123,000,000
Private Equity Funds [Member] | U.S. Plans
Change in Plan Assets
Fair value of plan assets at December 31	2,626,000,000			2,784,000,000	2,626,000,000		2,626,000,000
Private Equity Funds [Member] | Non-U.S. Plans
Change in Plan Assets
Fair value of plan assets at December 31	$ 352,000,000			$ 538,000,000	$ 352,000,000		$ 352,000,000