Retirement-Related Benefits (Details 1) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Retirement-Related Benefits:
Defined benefit and contribution pension plans - cost	$ 505	$ 408	$ 1,747	$ 1,280
Nonpension postretirement plans - cost	68	67	206	204
Total	$ 573	$ 475	$ 1,953	$ 1,484
Year-to-year percent change, defined benefit and contribution pension plans cost (as a percent)	23.90%		36.50%
Year-to-year percent change, Nonpension postretirement plans cost (as a percent)	0.30%		0.90%
Year-to-year percent change, total (as a percent)	20.60%		31.60%