Retirement-Related Benefits: (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Retirement-related plans cost
Defined benefit and contribution pension plan - cost	$ 636	$ 459	$ 1,310	$ 991
Nonpension postretirement plans - cost	71	89	151	174
Total	706	548	1,460	1,164
Year-to-year percent change, defined benefit and contribution pension plans cost	38.50%		32.20%
Year-to-year percent change, Nonpension postretirement plans cost	(21.00%)		(13.30%)
Year-to-year percent change, total	28.80%		25.40%
Defined benefit and contribution pension plan - cost U.S. Plans	138	81	298	223
Defined benefit and contribution pension plan - cost Non-U.S. Plans	497	378	1,011	768
Proceeds from Medicare Prescription Drug Improvement and Modernization Act of 2003	10.0		16.2
Defined Contribution U.S. Plans
Retirement-related plans cost
Cost of defined contribution plans	193	212	399	477
Defined Contribution Non-U.S. Plans
Retirement-related plans cost
Cost of defined contribution plans	148	156	300	319
Multi-employer Plans - Non-U.S. Plans
Retirement-related plans cost
Multi-employer plan/other costs	25	23	55	46
U.S. Defined Benefit Pension Plans
Retirement-related plans cost
Interest cost	494	548	990	1,098
Expected return on plan assets	(995)	(1,011)	(1,991)	(2,022)
Amortization of prior service costs/(credits)	2	3	5	5
Recognized actuarial losses	444	330	895	665
Total net periodic pension (income)/cost of defined benefit plans	(55)	(131)	(101)	(254)
Non-US Defined Benefit Pension Plans
Retirement-related plans cost
Service cost	120	111	251	224
Interest cost	376	444	758	894
Expected return on plan assets	(537)	(573)	(1,091)	(1,153)
Amortization of prior service costs/(credits)	(29)	(38)	(60)	(77)
Recognized actuarial losses	394	256	798	515
Curtailments and settlements	0	0		1
Total net periodic pension (income)/cost of defined benefit plans	349	222	711	449
Non-U.S. Defined Benefit and Multi-employer Plan
Retirement-related plans cost
Expected current year contributions to non-U.S. defined benefit plans			600
Year-to-date contributions to non-U.S. defined benefit plans			290
U.S. Defined Benefit Non Pension Postretirement Plans
Retirement-related plans cost
Service cost	9	9	17	18
Interest cost	40	51	82	100
Expected return on plan assets	0		(1)
Recognized actuarial losses	2	10	11	16
Total net periodic pension (income)/cost of defined benefit plans	51	70	109	134
Non-U.S. Defined Benefit Non Pension Postretirement Plans
Retirement-related plans cost
Service cost	2	2	5	5
Interest cost	15	16	31	33
Expected return on plan assets	(2)	(2)	(5)	(5)
Amortization of prior service costs/(credits)	(1)	(1)	(2)	(2)
Recognized actuarial losses	6	4	12	9
Curtailments and settlements			0
Total net periodic pension (income)/cost of defined benefit plans	$ 20	$ 19	$ 41	$ 39