Goodwill and Intangible Assets - Goodwill balance by business segment (Details)	3 Months Ended		6 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2019 USD ($)	Mar. 31, 2019 USD ($) segment	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($) segment	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($) item	Dec. 31, 2017 USD ($)
Goodwill Information
Number of business combinations completed						0
Purchased goodwill from acquisitions	$ 3,469,000,000			$ 3,469,000,000	$ 3,469,000,000
Goodwill acquired during the period which is deductible for tax purposes	0			0	0
Increase (decrease) in goodwill related to preliminary allocation of purchase price for prior acquisitions						$ 7,000,000
Goodwill
Balance at the beginning of the period		$ 10,051,000,000	$ 10,051,000,000		10,051,000,000	10,513,000,000
Acquisition activity					3,469,000,000	7,000,000
Divestiture activity					(49,000,000)	(272,000,000)
Translation and other					(27,000,000)	(197,000,000)
Balance at the end of the period	13,444,000,000			$ 13,444,000,000	13,444,000,000	10,051,000,000	$ 10,513,000,000
Number of business segments | segment		5		4
Amount of Goodwill impairment	0		0		0	0	0
Safety and Industrial
Goodwill
Balance at the beginning of the period		$ 4,716,000,000	4,716,000,000		4,716,000,000	5,077,000,000
Acquisition activity						7,000,000
Divestiture activity					(49,000,000)	(268,000,000)
Translation and other					(46,000,000)	(100,000,000)
Balance at the end of the period	4,621,000,000			$ 4,621,000,000	4,621,000,000	4,716,000,000	5,077,000,000
Transportation and Electronics
Goodwill
Balance at the beginning of the period		1,857,000,000	1,857,000,000		1,857,000,000	1,886,000,000
Translation and other					(27,000,000)	(29,000,000)
Balance at the end of the period	1,830,000,000			1,830,000,000	1,830,000,000	1,857,000,000	1,886,000,000
Health Care
Goodwill
Balance at the beginning of the period		3,248,000,000	3,248,000,000		3,248,000,000	3,317,000,000
Acquisition activity					3,469,000,000
Divestiture activity						(4,000,000)
Translation and other					22,000,000	(65,000,000)
Balance at the end of the period	6,739,000,000			6,739,000,000	6,739,000,000	3,248,000,000	3,317,000,000
Consumer
Goodwill
Balance at the beginning of the period		$ 230,000,000	$ 230,000,000		230,000,000	233,000,000
Translation and other					24,000,000	(3,000,000)
Balance at the end of the period	$ 254,000,000			$ 254,000,000	$ 254,000,000	$ 230,000,000	$ 233,000,000