v3.26.1
SPECIAL (GAINS) AND CHARGES - Narrative (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2024
Feb. 28, 2026
Dec. 31, 2025
Restructuring Cost and Reserve [Line Items]              
Restructuring charges incurred, pre-tax         $ 184.1    
Restructuring charges incurred, after tax         $ 151.5    
Resulting in a gain   $ 12.0          
Gain after tax   9.2          
Interest expense $ 6.6   $ 6.6        
Interest expense, after tax 5.7            
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Global surgical solutions business              
Restructuring Cost and Reserve [Line Items]              
Professional services   0.8   $ 2.4      
Services from professionals, net of tax   0.6   1.8      
Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServicesSold              
Restructuring Cost and Reserve [Line Items]              
Restructuring charges incurred, pre-tax 4.7 2.5 16.0 7.3      
Location, Statement of Income, Balance [Axis]: us-gaap:NonoperatingIncomeExpense              
Restructuring Cost and Reserve [Line Items]              
Other 13.6 2.0 14.5 11.0      
Other special gains and charges, after-tax 17.3 1.6 17.9 9.7      
Location, Statement of Income, Balance [Axis]: us-gaap:OtherNonrecurringIncomeExpense              
Restructuring Cost and Reserve [Line Items]              
Acquisition and integration activities 4.6 7.3 18.7 8.8      
Business combination and integration related costs, after tax 2.2 5.6 14.5 6.7      
Other 13.6 2.0 14.5 (11.0)      
Location, Statement of Income, Balance [Axis]: ecl:InterestExpenseNet              
Restructuring Cost and Reserve [Line Items]              
Interest expense 6.6 0.0 6.6 0.0      
One Ecolab Initiative Program              
Restructuring Cost and Reserve [Line Items]              
Restructuring charge expected to be incurred, pre-tax           $ 328.0  
Restructuring charge expected to be incurred, after tax           256.0  
Restructuring and related special charges, pre-tax           97.0  
Restructuring and related activities special charges, after tax           $ 76.0  
Restructuring charges incurred to date, pre-tax 250.2   250.2        
Restructuring charges incurred to date, after-tax 192.4   192.4        
Special charges to date 65.0   65.0        
Special charges to date, after tax 49.2   49.2        
Restructuring liability 83.4   83.4       $ 96.1
One Ecolab Initiative Program | Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServicesSold              
Restructuring Cost and Reserve [Line Items]              
Restructuring charges incurred, pre-tax 1.1 2.5 2.7 7.3      
One Ecolab Initiative Program | Location, Statement of Income, Balance [Axis]: us-gaap:OtherNonrecurringIncomeExpense              
Restructuring Cost and Reserve [Line Items]              
Restructuring charges incurred, pre-tax 27.7 26.5 59.1 65.9      
Professional services 4.9 11.6 10.4 16.4      
Services from professionals, net of tax 3.7 8.8 7.9 12.4      
One Ecolab Initiative Program | Employee Severance              
Restructuring Cost and Reserve [Line Items]              
Restructuring charges incurred, pre-tax 23.9 17.4 51.4 56.8      
Restructuring charges incurred, after tax 18.3 $ 13.2 38.9 $ 43.7      
Restructuring liability 75.9   75.9       92.5
Other Restructuring Plan              
Restructuring Cost and Reserve [Line Items]              
Restructuring charges incurred, pre-tax 4.1   13.8        
Restructuring charges incurred, after tax 3.3   11.1        
Prior Year Plans              
Restructuring Cost and Reserve [Line Items]              
Restructuring liability $ 10.8   $ 10.8       $ 8.8