Pensions and Other Postretirement Benefits Schedule of Net Benefit Costs (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
US Pension Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Service cost including administrative expenses	$ 102	$ 96	$ 203	$ 191
Interest cost	688	765	1,377	1,530
Expected return on plan assets	(974)	(979)	(1,948)	(1,957)
Amortization of prior service cost (credit)	(1)	(1)	(2)	(2)
Amortization of net actuarial (gains) losses	2	(23)	4	(46)
Curtailments, settlements and other	0	0	0	(2)
Net periodic pension and OPEB (income) expense	(183)	(142)	(366)	(286)
Non-US Pension Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Service cost including administrative expenses	95	112	195	205
Interest cost	195	263	391	525
Expected return on plan assets	(202)	(222)	(405)	(441)
Amortization of prior service cost (credit)	4	4	8	9
Amortization of net actuarial (gains) losses	59	41	117	80
Curtailments, settlements and other	107	(1)	107	1
Net periodic pension and OPEB (income) expense	258	197	413	379
Global OPEB Plans [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Service cost	6	6	12	11
Interest cost	59	69	119	137
Expected return on plan assets	0	0	0	0
Amortization of prior service cost (credit)	(3)	(4)	(6)	(8)
Amortization of net actuarial (gains) losses	9	2	17	4
Curtailments, settlements and other	0	0	0	0
Net periodic pension and OPEB (income) expense	$ 71	$ 73	$ 142	$ 144