Goodwill And Other Intangible Assets (Rollforward Of Goodwill) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Balance at beginning of year	$ 22,713	$ 22,581
Attributable to acquisitions	10,402	217	$ 1,276
Attributable to 2020 divestitures	(181)
Adjustments due to finalization of purchase price adjustments	(3)	(7)
Foreign currency translation and other	2,489	(78)
Balance at end of year	35,420	22,713	22,581
Operating segments | Life Sciences
Goodwill [Roll Forward]
Balance at beginning of year	13,472	13,311
Attributable to acquisitions	10,291	213
Attributable to 2020 divestitures	(181)
Adjustments due to finalization of purchase price adjustments	(3)	(7)
Foreign currency translation and other	2,233	(45)
Balance at end of year	25,812	13,472	13,311
Operating segments | Diagnostics
Goodwill [Roll Forward]
Balance at beginning of year	6,901	6,926
Attributable to acquisitions	0	3
Attributable to 2020 divestitures	0
Adjustments due to finalization of purchase price adjustments	0	0
Foreign currency translation and other	181	(28)
Balance at end of year	7,082	6,901	6,926
Operating segments | Environmental & Applied Solutions
Goodwill [Roll Forward]
Balance at beginning of year	2,340	2,344
Attributable to acquisitions	111	1
Attributable to 2020 divestitures	0
Adjustments due to finalization of purchase price adjustments	0	0
Foreign currency translation and other	75	(5)
Balance at end of year	$ 2,526	$ 2,340	$ 2,344