OPERATING SEGMENTS (Details) $ in Millions	3 Months Ended				12 Months Ended
	Mar. 31, 2025 USD ($)	Mar. 31, 2025 segment	Mar. 31, 2025 item	Mar. 31, 2024 USD ($)	Dec. 31, 2024 USD ($)
Number of operating segments aggregated for classification as reportable segments | segment		7
Number of operating units		7	7
Number of reportable segments | segment		4
Net sales	$ 3,695.0			$ 3,751.9
Cost of sales	2,060.2			2,128.1
Selling, general and administrative expenses	1,050.0			1,077.7
Special (gains) and charges	29.5			28.2
Operating Income (Loss)	555.3			517.9
Previously Reported | Valued at 2024 Management Rates
Net sales					$ 15,741.4
Operating Income (Loss)					2,802.4
Previously Reported | Valued at 2025 Management Rates
Net sales					15,741.4
Operating Income (Loss)					2,802.4
Global Water
Net sales	1,826.4			1,838.9
Global Institutional and Specialty
Net sales	1,418.0			1,480.2
Global Life Sciences
Net sales	170.0			166.7
Global Pest Elimination
Net sales	280.6			266.1
Operating segment
Net sales	3,652.1			3,621.5
Cost of sales	2,035.7			2,054.8
Selling, general and administrative expenses	1,039.7			1,050.4
Special (gains) and charges	29.3			28.3
Operating Income (Loss)	547.4			488.0
Operating segment | Previously Reported | Valued at 2024 Management Rates
Net sales					15,873.0
Cost of sales					8,974.2
Selling, general and administrative expenses					4,252.6
Special (gains) and charges					(188.9)
Operating Income (Loss)					2,835.1
Operating segment | Previously Reported | Valued at 2025 Management Rates
Net sales					15,273.4
Cost of sales					8,629.5
Selling, general and administrative expenses					4,133.8
Special (gains) and charges					(188.7)
Operating Income (Loss)					2,698.8
Operating segment | Purchase Price Adjustments | Changes in Currency Rates
Net sales					(599.6)
Cost of sales					(344.7)
Selling, general and administrative expenses					(118.8)
Special (gains) and charges					0.2
Operating Income (Loss)					(136.3)
Operating segment | Global Water
Net sales	1,800.5			1,755.0
Cost of sales	1,073.6			1,050.5
Selling, general and administrative expenses	466.9			460.9
Operating Income (Loss)	260.0			243.6
Operating segment | Global Water | Previously Reported | Valued at 2024 Management Rates
Net sales					7,857.2
Cost of sales					4,691.2
Selling, general and administrative expenses					1,865.4
Operating Income (Loss)					1,300.6
Operating segment | Global Water | Previously Reported | Valued at 2025 Management Rates
Net sales					7,483.4
Cost of sales					4,470.9
Selling, general and administrative expenses					1,805.3
Operating Income (Loss)					1,207.2
Operating segment | Global Water | Purchase Price Adjustments | Changes in Currency Rates
Net sales					(372.6)
Cost of sales					(222.3)
Selling, general and administrative expenses					(63.2)
Operating Income (Loss)					(87.1)
Operating segment | Global Water | Purchase Price Adjustments | Segment Changes
Net sales					(1.2)
Cost of sales					2.0
Selling, general and administrative expenses					3.1
Operating Income (Loss)					(6.3)
Operating segment | Global Institutional and Specialty
Net sales	1,406.5			1,446.9
Cost of sales	705.3			770.6
Selling, general and administrative expenses	402.6			418.9
Operating Income (Loss)	298.6			257.4
Operating segment | Global Institutional and Specialty | Previously Reported | Valued at 2024 Management Rates
Net sales					5,413.9
Cost of sales					2,727.5
Selling, general and administrative expenses					1,503.7
Operating Income (Loss)					1,182.7
Operating segment | Global Institutional and Specialty | Previously Reported | Valued at 2025 Management Rates
Net sales					5,979.4
Cost of sales					3,131.0
Selling, general and administrative expenses					1,646.2
Operating Income (Loss)					1,202.2
Operating segment | Global Institutional and Specialty | Purchase Price Adjustments | Changes in Currency Rates
Net sales					(160.5)
Cost of sales					(87.1)
Selling, general and administrative expenses					(38.7)
Operating Income (Loss)					(34.7)
Operating segment | Global Institutional and Specialty | Purchase Price Adjustments | Segment Changes
Net sales					726.0
Cost of sales					490.6
Selling, general and administrative expenses					181.2
Operating Income (Loss)					54.2
Operating segment | Global Life Sciences
Net sales	167.0			159.3
Cost of sales	90.4			84.6
Selling, general and administrative expenses	51.4			55.4
Operating Income (Loss)	25.2			19.3
Operating segment | Global Life Sciences | Previously Reported | Valued at 2024 Management Rates
Net sales					1,434.1
Cost of sales					895.1
Selling, general and administrative expenses					391.8
Operating Income (Loss)					147.2
Operating segment | Global Life Sciences | Previously Reported | Valued at 2025 Management Rates
Net sales					670.5
Cost of sales					382.6
Selling, general and administrative expenses					196.1
Operating Income (Loss)					91.8
Operating segment | Global Life Sciences | Purchase Price Adjustments | Changes in Currency Rates
Net sales					(38.8)
Cost of sales					(19.8)
Selling, general and administrative expenses					(6.3)
Operating Income (Loss)					(12.7)
Operating segment | Global Life Sciences | Purchase Price Adjustments | Segment Changes
Net sales					(724.8)
Cost of sales					(492.7)
Selling, general and administrative expenses					(189.4)
Operating Income (Loss)					(42.7)
Operating segment | Global Pest Elimination
Net sales	278.1			260.3
Cost of sales	161.7			147.5
Selling, general and administrative expenses	70.3			66.3
Operating Income (Loss)	46.1			46.5
Operating segment | Global Pest Elimination | Previously Reported | Valued at 2024 Management Rates
Net sales					1,167.8
Cost of sales					655.0
Selling, general and administrative expenses					292.4
Operating Income (Loss)					220.4
Operating segment | Global Pest Elimination | Previously Reported | Valued at 2025 Management Rates
Net sales					1,140.1
Cost of sales					639.8
Selling, general and administrative expenses					290.6
Operating Income (Loss)					209.7
Operating segment | Global Pest Elimination | Purchase Price Adjustments | Changes in Currency Rates
Net sales					(27.7)
Cost of sales					(15.3)
Selling, general and administrative expenses					(6.9)
Operating Income (Loss)					(5.5)
Operating segment | Global Pest Elimination | Purchase Price Adjustments | Segment Changes
Cost of sales					0.1
Selling, general and administrative expenses					5.1
Operating Income (Loss)					(5.2)
Operating segment | Corporate
Cost of sales	4.7			1.6
Selling, general and administrative expenses	48.5			48.9
Special (gains) and charges	29.3			28.3
Operating Income (Loss)	(82.5)			(78.8)
Currency impact
Net sales	42.9			130.4
Operating Income (Loss)	$ 7.9			$ 29.9
Currency impact | Previously Reported | Valued at 2024 Management Rates
Net sales					(131.6)
Operating Income (Loss)					(32.7)
Currency impact | Previously Reported | Valued at 2025 Management Rates
Net sales					468.0
Operating Income (Loss)					103.6
Currency impact | Purchase Price Adjustments | Changes in Currency Rates
Net sales					599.6
Operating Income (Loss)					136.3
Corporate | Previously Reported | Valued at 2024 Management Rates
Cost of sales					5.4
Selling, general and administrative expenses					199.3
Special (gains) and charges					(188.9)
Operating Income (Loss)					(15.8)
Corporate | Previously Reported | Valued at 2025 Management Rates
Cost of sales					5.2
Selling, general and administrative expenses					195.6
Special (gains) and charges					(188.7)
Operating Income (Loss)					(12.1)
Corporate | Purchase Price Adjustments | Changes in Currency Rates
Cost of sales					(0.2)
Selling, general and administrative expenses					(3.7)
Special (gains) and charges					0.2
Operating Income (Loss)					$ 3.7