Goodwill and Intangible Assets - Goodwill balance by business segment (Details)	9 Months Ended
	Sep. 30, 2020 USD ($) item
Goodwill Information
Number of business combinations completed | item	0
Goodwill
Balance at the beginning of the period	$ 13,444,000,000
Acquisition activity	(34,000,000)
Divestiture activity	(29,000,000)
Translation and other	154,000,000
Balance at the end of the period	13,535,000,000
Amount of Goodwill impairment	0
Safety and Industrial
Goodwill
Balance at the beginning of the period	4,621,000,000
Translation and other	(7,000,000)
Balance at the end of the period	4,614,000,000
Transportation and Electronics
Goodwill
Balance at the beginning of the period	1,830,000,000
Divestiture activity	(10,000,000)
Translation and other	13,000,000
Balance at the end of the period	1,833,000,000
Health Care
Goodwill
Balance at the beginning of the period	6,739,000,000
Acquisition activity	(34,000,000)
Divestiture activity	(19,000,000)
Translation and other	143,000,000
Balance at the end of the period	6,829,000,000
Consumer
Goodwill
Balance at the beginning of the period	254,000,000
Translation and other	5,000,000
Balance at the end of the period	$ 259,000,000