Document and Entity Information [Abstract] Document Information [Table] Legal Entity [Axis] Entity [Domain] Represents the Retirement Plan Number 003 being ECOLAB SAVINGS PLAN AND ESOP. E B P 003 [Member] ECOLAB SAVINGS PLAN AND ESOP Document Information [Line Items] Document Type Entity Registrant Name Entity Central Index Key Amendment Flag STATEMENTS OF NET ASSETS AVAILABLE FOR BENEFITS EBP, Statement of Net Asset Available for Benefit [Table] Investment Type [Axis] Investments [Domain] EBP, Employer, Common Stock [Member] Common stock Mutual Fund [Member] Registered investment companies Common Collective Trust [Member] Common/collective trusts Interest-Bearing Deposits [Member] Interest bearing cash EBP, Statement of Net Asset Available for Benefit [Line Items] STATEMENTS OF NET ASSETS AVAILABLE FOR BENEFITS EBP, Investment, Fair and Contract Value [Abstract] Investments at fair value EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value Investment at fair value EBP, Investment, Excluding Plan Interest in Master Trust, Contract Value Fully-benefit responsive investment contract at contract value EBP, Investment, Excluding Plan Interest in Master Trust, Fair and Contract Value Total investments EBP, Receivable [Abstract] Receivables EBP, Note Receivable from Participant Notes receivable from participants EBP, Investment Income, Receivable Dividends receivable EBP, Employer Contribution, Receivable Employer contributions receivable EBP, Participant Contribution, Receivable Employee contributions receivable EBP, Receivable Total receivables EBP, Net Asset Available for Benefit End of year Beginning of year Net assets available for benefits per the financial statements Net assets available for benefits STATEMENT OF CHANGES IN NET ASSETS AVAILABLE FOR BENEFITS EBP, Statement of Change in Net Asset Available for Benefit [Table] EBP, Statement of Change in Net Asset Available for Benefit [Line Items] STATEMENT OF CHANGES IN NET ASSETS AVAILABLE FOR BENEFITS EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment [Abstract] Investment results EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Unrealized Gain (Loss) on Investment Net appreciation in fair value of investments EBP, Change in Net Asset Available for Benefit, Increase from Interest and Dividend Income on Investment Dividends and interest EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment Total investment results EBP, Change in Net Asset Available for Benefit, Increase from Interest Income on Note Receivable from Participant Interest income on notes receivable from participants EBP, Change in Net Asset Available for Benefit, Increase from Contribution [Abstract] Contributions EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Excluding Rollover Participants EBP, Change in Net Asset Available for Benefit, Increase from Employer Contribution, Cash and Noncash Employer EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Rollover Rollovers EBP, Change in Net Asset Available for Benefit, Increase from Contribution Total contributions EBP, Change in Net Asset Available for Benefit, Decrease [Abstract] Deductions EBP, Change in Net Asset Available for Benefit, Decrease from Payment to Participant Distributions to participants EBP, Change in Net Asset Available for Benefit, Decrease from Administrative Expense Plan expenses EBP, Change in Net Asset Available for Benefit, Decrease Total deductions EBP, Change in Net Asset Available for Benefit, Increase (Decrease) Net increase in net assets available for benefits per the financial statements Net increase EBP, Change in Net Asset Available for Benefit, Increase (Decrease) [Abstract] Net assets available for benefits DESCRIPTION OF PLAN EBP, Description of Plan [Table] EBP, Description of Plan [Line Items] DESCRIPTION OF PLAN EBP, Description of Plan [Text Block] DESCRIPTION OF PLAN SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES EBP, Accounting Policy [Table] EBP, Accounting Policy [Line Items] SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES EBP, Summary of Accounting Policy [Text Block] SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES FAIR VALUE MEASUREMENTS EBP, Investment, Fair Value and NAV [Table] EBP, Investment, Fair Value and NAV [Line Items] FAIR VALUE MEASUREMENTS EBP, Investment, Fair Value and NAV [Text Block] FAIR VALUE MEASUREMENTS INVESTMENT CONTRACTS EBP, Fully Benefit-Responsive Investment Contract [Table] EBP, Fully Benefit-Responsive Investment Contract [Line Items] INVESTMENT CONTRACTS EBP, Fully Benefit-Responsive Investment Contract [Text Block] INVESTMENT CONTRACTS TAX STATUS EBP, Tax Status [Table] EBP, Tax Status [Line Items] TAX STATUS EBP, Tax Status [Text Block] TAX STATUS RELATED PARTY AND PARTY-IN-INTEREST TRANSACTIONS EBP, Related Party and Party-in-Interest Transactions [Table] EBP, Related Party and Party-in-Interest Transactions [Line Items] RELATED PARTY AND PARTY-IN-INTEREST TRANSACTIONS EBP, Related Party and Party-in-Interest Transactions [Text Block] RELATED PARTY AND PARTY-IN-INTEREST TRANSACTIONS RECONCILIATION OF FINANCIAL STATEMENTS TO FORM 5500 EBP, Reconciliation of Financial Statement to Form 5500 [Table] EBP, Reconciliation of Financial Statement to Form 5500 [Line Items] RECONCILIATION OF FINANCIAL STATEMENTS TO FORM 5500 EBP, Reconciliation of Financial Statement to Form 5500 [Text Block] RECONCILIATION OF FINANCIAL STATEMENTS TO FORM 5500 SCHEDULE H, LINE 4i - SCHEDULE OF ASSETS (HELD AT END OF YEAR) EBP, Schedule of Asset Held for Investment [Table] EBP, Schedule of Asset Held for Investment [Line Items] SCHEDULE H, LINE 4i - SCHEDULE OF ASSETS (HELD AT END OF YEAR) EBP, Schedule of Asset Held for Investment [Text Block] SCHEDULE H, LINE 4i - SCHEDULE OF ASSETS (HELD AT END OF YEAR) EBP, Basis of Accounting [Policy Text Block] Basis of Presentation EBP, Use of Estimate [Policy Text Block] Use of Estimates EBP, Investment [Policy Text Block] Valuation of Investments and Income Recognition EBP, Note Receivable from Participant [Policy Text Block] Notes Receivable from Participants EBP, Contribution [Policy Text Block] Contributions EBP, Risk and Uncertainty [Policy Text Block] Risks and Uncertainties Disclosure of accounting policy for concentration of market risk of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Employee Benefit Plan, Concentration of Market Risk [Policy Text Block] Concentration of Market Risk EBP, Payment to Participant [Policy Text Block] Distributions to Participants EBP, Expense [Policy Text Block] Plan Expenses EBP, Subsequent Event [Policy Text Block] Subsequent Events EBP, Investment, Fair Value and NAV [Table Text Block] Schedule of Plan's Assets Fair Value Hierarchy Disclosure of investments whose fair value is estimated using net asset value (NAV) per share (or its equivalent), including related information such as fair value, unfunded commitments, redemption frequency, redemption notice periods, and other terms and conditions associated with the investments. Employee Benefit Plan, Investment, Fair Value Estimated Using NAV Per Share [Table Text Block] Tabular disclosure of additional disclosures of Plan's investments whose fair value is estimated using NAV per share EBP, Reconciliation of Financial Statement to Form 5500 [Table Text Block] Reconciliation of net assets available for benefits per the financial statements Statistical Measurement [Axis] Statistical Measurement [Domain] Maximum [Member] Maximum Minimum [Member] Minimum Scenario [Axis] Scenario [Domain] Represents the information pertaining to scenario being employee contribution up to 4%. Scenario, Employee Contribution Up To 4% [Member] Employee contribution up to 4% Represents the information pertaining to scenario being employee contribution over 4% and up to 8%. Scenario, Employee Contribution Over 4% and Up To 8% [Member] Employee contribution over 4% and up to 8% Represents the minimum number of regularly scheduled hours per week an employee must be scheduled to work to be immediately eligible to participate in the employee benefit plan. Employee Benefit Plan, Minimum Scheduled Hours per Week Required for Plan Eligibility Minimum service period for Plan eligibility of week (in hours) Represents the minimum number of hours of service an employee must complete during the specified eligibility period to become eligible to participate in the employee benefit plan. Employee Benefit plan, Minimum Hours of Service Required for Plan Eligibility Minimum service period for Plan eligibility of twelve month service period (in hours) EBP, Participant Contribution, Pretax, Maximum Annual Compensation to Total Compensation, Percentage Employee contribution (in percentage) EBP, Participant Contribution, Pretax, Maximum Annual Compensation, Amount Employee contribution EBP, Employer Contribution, Participant Compensation Matched, Percentage Percentage of participant eligible compensation EBP, Employer Contribution, Matching Percentage Employer contribution Threshold age that participant must attain for withdrawals in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Employee Benefit Plan, Participant Withdrawals Threshold Age Threshold age for withdrawal (in age) EBP, Note Receivable from Participant, Account, Maximum Borrowing, Amount Note receivable, maximum borrowing amount EBP, Note Receivable from Participant, Account, Maximum Borrowing, to Total Account, Percentage Note receivable, maximum borrowing percentage Maximum repayment period permitted for participant general purpose loans under the employee benefit plan. Employee Benefit Plan, Participant Loan, General Purpose, Maximum Repayment Term General purpose loan, maximum repayment term Maximum repayment period permitted for participant loans used for the purchase of a primary residence under the employee benefit plan. Employee Benefit Plan, Participant Loan, Primary Residence, Maximum Repayment Term Primary residence loan, maximum repayment term EBP, Asset Held for Investment, Participant Loan, Interest Rate Interest rates of notes receivable from participants Number of minimum notes of a participants that can be outstanding at any time. Employee Benefit Plan, Number Of Minimum Notes Outstanding At Anytime Minimum number of notes that can be outstanding at any time Minimum dollar amount in which a participant may transfer amounts between available investment options under the employee benefit plan. Employee Benefit Plan, Participant Account, Minimum Investment Transfer Amount Minimum transfer amount EBP, Note Receivable from Participant, Allowance for Credit Loss Allowance for credit losses EBP, Risk and Uncertainty, Concentration of Investment at Fair Value to Net Assets, Percentage Concentration of market risk (in percentage) Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] Total Fair Value, Inputs, Level 1 [Member] Level 1 Fair Value Measured at Net Asset Value Per Share [Member] Net asset value per share Percentage of minimum or contractually guaranteed rate of return that the contract provider guarantees to participants' balances under the investment contract. Employee Benefit Plan, Fully Benefit Responsive Investment Contract, Guaranteed Interest Rate Guaranteed interest rate EBP, Tax Determination Letter, Obtained [true false] Determination letter obtained EBP, Tax Determination Letter, Date Determination letter date EBP, Tax Qualification Status [Extensible Enumeration] Tax qualification status EBP, Related Party and Party-in-Interest [Axis] EBP, Related Party and Party-in-Interest [Domain] Employer of participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)). Employee Benefit Plan, Employer [Member] Ecolab Inc. EBP, Investment, Number of Shares Number of shares held EBP, Investment Acquired, Excluding Plan Interest in Master Trust, Cost Purchase of investment EBP, Investment Sold, Excluding Plan Interest in Master Trust, Selling Price Sale of investment EBP, Form 5500 Caption, Net Assets [Abstract] Reconciliation of net assets available for benefits EBP, Reconciliation to Form 5500, Net Asset Available for Benefit, Contract Value to Current Value Adjustment Fully benefit-responsive investment contracts value adjustment EBP, Form 5500 Caption, Net Assets Net assets available for benefits per Form 5500 EBP, Form 5500 Caption, Net Income (Loss) [Abstract] Reconciliation of the net increase in net assets available for benefits per the Plan financial statements Amount of the increase in net assets available for benefits included in the reconciliation to Form 5500 resulting from the reversal of the prior year's adjustment for fully benefit-responsive investment contracts. Employee Benefit Plan, Reconciliation To Form 5500, Change In Net Asset Available For Benefit Increase From Prior Year Fully Benefit-Responsive Investment Contracts Value Adjustment Prior year fully benefit-responsive investment contracts value adjustment Amount of the decrease in net assets available for benefits included in the reconciliation to Form 5500 resulting from the current year's adjustment for fully benefit-responsive investment contracts. Employee Benefit Plan, Reconciliation To Form 5500, Change In Net Asset Available For Benefit Decrease From Current Year Fully Benefit-Responsive Investment Contracts Value Adjustment Current year fully benefit-responsive investment contracts value adjustment EBP, Form 5500 Caption, Net Income (Loss) Total increase in net assets available for benefits per Form 5500 Investment, Identifier [Axis] Entity Tax Identification Number Entity tax identification number EBP, Plan Number Plan number EBP, Investment, Issuer Name [Extensible Enumeration] Investment issuer name EBP, Investment, Current Value, Type [Extensible Enumeration] Investment current value type EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Current Value Current Value EBP, Asset Held for Investment, Participant Loan, Maturity Date EBP, Asset Held for Investment Total assets EBP, Asset Held for Investment, Party-in-Interest [true false] Asset held for investment, party-in-interest