Retirement-Related Benefits (Narrative) (Details 4) - USD ($) $ in Millions	3 Months Ended				6 Months Ended			12 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2014
Non-U.S. Defined Benefit and Multi-employer Plan
Expected current year contributions to non-U.S. defined benefit plans					$ 600
Year-to-date contributions to non-U.S. defined benefit plans					186
Non-US Defined Benefit Pension Plans
Multi-employer plans/other costs	$ 8		$ 16		$ 256		$ 95
Non-US Defined Benefit Pension Plans | SG&A expense | Litigation in Spain regarding defined benefit and defined contribution plans
Multi-employer plans/other costs		$ 230		$ 55		$ 93		$ 148