Acquisitions, Dispositions, Goodwill and Other Intangible Assets (Intangible Assets) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ 29,819	$ 29,559
Accumulated Amortization	7,779	7,053
Unamortized: Trademarks and Other	3,923	3,918
Total Intangible Assets Gross Excluding Goodwill	33,742	33,477
Service portfolios [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	2,179	2,164
Accumulated Amortization	1,656	1,608
Patents and trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	361	361
Accumulated Amortization	245	236
Collaboration intangible assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	4,681	4,509
Accumulated Amortization	779	649
Customer relationships and other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Amount	22,598	22,525
Accumulated Amortization	$ 5,099	$ 4,560