Retirement-Related Benefits (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended										12 Months Ended	3 Months Ended	12 Months Ended	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 Defined Contribution U.S. Plans	Mar. 31, 2013 Defined Contribution U.S. Plans	Mar. 31, 2014 Defined Contribution Non-U.S. Plans	Mar. 31, 2013 Defined Contribution Non-U.S. Plans	Mar. 31, 2014 Multi-employer Plans - Non U.S. Plans Spain Pending Litigation SG&A expense	Mar. 31, 2014 U.S. Defined Benefit Pension Plans	Mar. 31, 2013 U.S. Defined Benefit Pension Plans	Mar. 31, 2014 U.S. Defined Benefit Pension Plans Equity securities	Dec. 31, 2013 U.S. Defined Benefit Pension Plans Equity securities	Mar. 31, 2014 U.S. Defined Benefit Pension Plans Debt securities	Dec. 31, 2013 U.S. Defined Benefit Pension Plans Debt securities	Mar. 31, 2014 Non-US Defined Benefit Pension Plans	Mar. 31, 2013 Non-US Defined Benefit Pension Plans	Mar. 31, 2014 Non-U.S. Defined Benefit and Multi-employer Plan	Mar. 31, 2014 U.S. Defined Benefit Non Pension Postretirement Plans	Mar. 31, 2013 U.S. Defined Benefit Non Pension Postretirement Plans	Mar. 31, 2014 Non-U.S. Defined Benefit Non Pension Postretirement Plans	Mar. 31, 2013 Non-U.S. Defined Benefit Non Pension Postretirement Plans
Retirement-related plans cost
Service cost														$ 116	$ 131		$ 7	$ 9	$ 2	$ 3
Interest cost								555	496					390	382		45	42	16	16
Expected return on plan assets								(1,024)	(995)					(572)	(554)		0	0	(2)	(2)
Amortization of prior service costs/(credits)								2	2					(29)	(31)		(2)		(1)	(1)
Recognized actuarial losses								269	451					360	404		0	8	3	6
Curtailments and settlements														4	0
Multi-employer plans/other costs							55							79	30
Total net periodic pension (income)/cost of defined benefit plans								(198)	(46)					348	363		50	58	17	22
Cost of defined contribution plans			191	206	133	151
Defined benefit and contribution pension plan - cost	474	674
Nonpension postretirement plans - cost	67	80
Total	541	754
Year-to-year percent change, defined benefit and contribution pension plans cost	(29.60%)
Year-to-year percent change, Nonpension postretirement plans cost	(16.00%)
Year-to-year percent change, total	(28.20%)
Expected current year contributions to non-U.S. defined benefit plans																600
Year-to-date contributions to non-U.S. defined benefit plans																126
Defined benefit and contribution pension plan - cost U.S. Plans	(7)	160
Defined benefit and contribution pension plan - cost Non U.S. Plans	481	514
Proceeds from Medicare Prescription Drug Improvement and Modernization Act of 2003	$ 5.4	$ 6.1
Target allocation (as a percent)										32.00%	42.00%	57.00%	47.00%
Expected long-term returns on plan assets (as a percent)								7.75%