Retirement-Related Benefits (Details 2) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Retirement-related plans cost
Total defined benefit and contribution plans cost recognized in the Consolidated Statement of Earnings	$ 505	$ 408	$ 1,747	$ 1,280
U.S. Defined Benefit Pension Plans
Retirement-related plans cost
Interest cost	507	553	1,521	1,659
Expected return on plan assets	(988)	(1,024)	(2,965)	(3,072)
Amortization of prior service costs/(credits)	2	2	7	7
Recognized actuarial losses	414	264	1,241	792
Total net periodic pension / nonpension (income)/cost of defined benefit plans	(65)	(205)	(196)	(614)
Non-US Defined Benefit Pension Plans
Retirement-related plans cost
Service cost	116	113	339	346
Interest cost	270	385	810	1,170
Expected return on plan assets	(481)	(565)	(1,446)	(1,715)
Amortization of prior service costs/(credits)	(24)	(28)	(74)	(85)
Recognized actuarial losses	392	351	1,186	1,072
Curtailments and settlements	11	7	19	20
Multi-employer plans/other costs	16	36	272	131
Total net periodic pension / nonpension (income)/cost of defined benefit plans	300	300	1,107	938
U.S. Defined Benefit Non Pension Postretirement Plans
Retirement-related plans cost
Service cost	6	7	18	20
Interest cost	41	47	122	140
Amortization of prior service costs/(credits)	(2)	(2)	(6)	(6)
Recognized actuarial losses	10	0	29	0
Total net periodic pension / nonpension (income)/cost of defined benefit plans	55	51	164	154
Non-U.S. Defined Benefit Non Pension Postretirement Plans
Retirement-related plans cost
Service cost	2	1	5	5
Interest cost	12	16	39	48
Expected return on plan assets	(2)	(2)	(5)	(7)
Amortization of prior service costs/(credits)	(1)	(1)	(4)	(4)
Recognized actuarial losses	2	3	7	8
Curtailments and settlements	0	0	0	0
Total net periodic pension / nonpension (income)/cost of defined benefit plans	$ 13	$ 16	$ 42	$ 50