Acquisitions, Dispositions, Goodwill and Other Intangible Assets (Intangible Assets) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ 29,822	$ 29,559
Accumulated Amortization	8,026	7,053
Unamortized: Trademarks and Other	3,890	3,918
Total Intangible Assets Gross Excluding Goodwill	33,712	33,477
Service portfolios [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	2,105	2,164
Accumulated Amortization	1,607	1,608
Patents and trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	353	361
Accumulated Amortization	244	236
Collaboration intangible assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	4,770	4,509
Accumulated Amortization	857	649
Customer relationships and other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	22,594	22,525
Accumulated Amortization	$ 5,318	$ 4,560