Retirement-Related Benefits: (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Retirement-related plans cost
Defined benefit and contribution pension plan - cost	$ 532	$ 432
Nonpension postretirement plans - cost	84	86
Total	616	517
Year-to-year percent change, defined benefit and contribution pension plans cost	23.20%
Year-to-year percent change, Nonpension postretirement plans cost	(1.80%)
Year-to-year percent change, total	19.00%
Proceeds from Medicare Prescription Drug Improvement and Modernization Act of 2003	16.5
Defined Benefit Pension Plans | U.S. Plan(s)
Retirement-related plans cost
Interest cost	550	620
Expected return on plan assets	(1,011)	(1,015)
Amortization of prior service costs/(credits)	2	2
Recognized actuarial losses	336	211
Total net periodic pension (income)/cost of defined benefit plans	(122)	(182)
Cost of defined contribution plans	264	265
Defined benefit and contribution pension plan - cost	142	82
Defined Benefit Pension Plans | Non-U.S. Plans
Retirement-related plans cost
Service cost	112	131
Interest cost	450	454
Expected return on plan assets	(580)	(620)
Amortization of prior service costs/(credits)	(39)	(40)
Recognized actuarial losses	259	245
Curtailments and settlements	1	0
Multi-employer plan/other costs	23	34
Total net periodic pension (income)/cost of defined benefit plans	227	204
Cost of defined contribution plans	163	146
Defined benefit and contribution pension plan - cost	390	349
Expected current year contributions to non-U.S. defined benefit plans	800
Year-to-date contributions to non-U.S. defined benefit plans	159
Nonpension Postretirement Plans | U.S. Plan(s)
Retirement-related plans cost
Service cost	9	8
Interest cost	49	59
Recognized actuarial losses	6
Nonpension postretirement plans - cost	64	67
Nonpension Postretirement Plans | Non-U.S. Plans
Retirement-related plans cost
Service cost	2	3
Interest cost	17	17
Expected return on plan assets	(3)	(3)
Amortization of prior service costs/(credits)	(1)	(1)
Recognized actuarial losses	4	3
Nonpension postretirement plans - cost	$ 20	$ 19