Retirement-Related Benefits (Details 1) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Retirement-Related Benefits:
Defined benefit and contribution pension plans - cost	$ 439	$ 749
Nonpension postretirement plans - cost	60	71
Total	$ 499	$ 820
Year-to-year percent change, defined benefit and contribution pension plans cost (as a percent)	(41.40%)
Year-to-year percent change, Nonpension postretirement plans cost (as a percent)	(15.90%)
Year-to-year percent change, total (as a percent)	(39.20%)