EARNINGS ATTRIBUTABLE TO ECOLAB PER COMMON SHARE ("EPS") (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Computations of the basic and diluted earnings attributable to Ecolab per share amounts
Net income attributable to Ecolab	$ 736.5	$ 404.0	$ 1,639.5	$ 967.1
Weighted-average common shares outstanding
Basic (in shares)	283.6	285.1	284.6	284.9
Effect of dilutive stock options and units (in shares)	2.4	1.8	2.2	1.5
Diluted (in shares)	286.0	286.9	286.8	286.4
Earnings attributable to Ecolab per common share
Basic EPS (in dollars per share)	$ 2.60	$ 1.42	$ 5.76	$ 3.39
Diluted EPS (in dollars per share)	$ 2.58	$ 1.41	$ 5.72	$ 3.38
Anti-dilutive securities excluded from the computation of diluted EPS		2.3		3.5