Pensions and Other Postretirement Benefits Schedule of Net Benefit Costs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
US Pension Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Service cost including administrative expenses	$ 101	$ 94	$ 304	$ 285
Interest cost	689	765	2,066	2,295
Expected return on plan assets	(974)	(978)	(2,922)	(2,935)
Amortization of prior service cost (credit)	(1)	(1)	(3)	(3)
Amortization of net actuarial (gains) losses	2	(22)	6	(68)
Curtailments, settlements and other	0	3	0	1
Net periodic pension and OPEB (income) expense	(183)	(139)	(549)	(425)
Non-US Pension Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Service cost	116	92	311	297
Interest cost	184	259	575	784
Expected return on plan assets	(193)	(221)	(598)	(662)
Amortization of prior service cost (credit)	3	4	11	13
Amortization of net actuarial (gains) losses	58	37	175	117
Curtailments, settlements and other	1	3	108	4
Net periodic pension and OPEB (income) expense	169	174	582	553
Global OPEB Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Service cost	6	7	18	18
Interest cost	59	66	178	203
Expected return on plan assets	0	0	0	0
Amortization of prior service cost (credit)	(4)	(4)	(10)	(12)
Amortization of net actuarial (gains) losses	10	2	27	6
Curtailments, settlements and other	0	0	0	0
Net periodic pension and OPEB (income) expense	$ 71	$ 71	$ 213	$ 215