Document and Entity Information Document Information [Table] Document Information [Line Items] Document and Entity Information Document Type Document Quarterly Report Document Period End Date Document Transition Report Entity File Number Entity Registrant Name Entity Incorporation, State or Country Code Entity Tax Identification Number Entity Address, Address Line One Entity Address, City or Town Entity Address, State or Province Entity Address, Postal Zip Code City Area Code Local Phone Number Title of 12(b) Security Trading Symbol Security Exchange Name Entity Current Reporting Status Entity Interactive Data Current Entity Filer Category Entity Small Business Entity Emerging Growth Company Entity Shell Company Entity Common Stock, Shares Outstanding Entity Central Index Key Current Fiscal Year End Date Document Fiscal Year Focus Document Fiscal Period Focus Amendment Flag CONSOLIDATED STATEMENTS OF INCOME Statement [Table] Products and Services [Axis] Products and Services [Domain] Product and equipment. Product and equipment sales Product and sold equipment Service and lease. Service and lease sales Service and lease equipment Statement [Line Items] Statement Revenue from Contract with Customer, Excluding Assessed Tax Net sales Net Sales Cost of Goods and Services Sold COS Cost of sales Cost of Sales Selling, General and Administrative Expense SG&A Selling, general and administrative expenses Selling, General and Administrative Expense Other Nonrecurring (Income) Expense Special (gains) and charges Other (income) expense Special (Gains) and Charges Operating Income (Loss) Operating Income Operating income Operating Income (Loss) Nonoperating Income (Expense) Other (income) expense The cost of borrowed funds accounted for as interest that was charged against earnings during the period net of income derived from investments in debt securities and on cash and cash equivalents the earnings of which reflect the time value of money or transactions in which the payments are for the use or forbearance of money. Interest Expense, Net Interest expense, net Interest expense, net Interest (income) expense, net Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest Income before income taxes Income Tax Expense (Benefit) Provision for income taxes Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net income including noncontrolling interest Net income including noncontrolling interest Net income Net Income (Loss) Attributable to Noncontrolling Interest Net income attributable to noncontrolling interest Net income attributable to Ecolab Net income attributable to Ecolab Earnings Per Share [Abstract] Earnings attributable to Ecolab per common share Earnings Per Share, Basic Basic (in dollars per share) Basic EPS (in dollars per share) Earnings Per Share, Diluted Diluted EPS (in dollars per share) Diluted EPS (in dollars per share) Weighted Average Number of Shares Outstanding, Diluted [Abstract] Weighted-average common shares outstanding Weighted Average Number of Shares Outstanding, Basic Basic (in shares) Weighted Average Number of Shares Outstanding, Diluted Diluted (in shares) Diluted (in shares) Product and equipment, and service and lease. Product and equipment, and service and lease Income Statement Location [Axis] Income Statement Location [Domain] Cost of sales COS CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME Other Comprehensive Income (Loss), Net of Tax [Abstract] Other comprehensive income (loss), net of tax Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax [Abstract] Foreign currency translation adjustments Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax Foreign currency translation Gain (Loss) on Derivative Used in Net Investment Hedge, Net of Tax Total revaluation gain (loss), net of tax Gain (loss) on net investment hedges Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Total foreign currency translation adjustments Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax Derivatives and hedging instruments Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax [Abstract] Pension and postretirement benefits Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax Pension and postretirement benefits Other Comprehensive Income (Loss), Net of Tax Subtotal Other comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Total comprehensive income, including noncontrolling interest Comprehensive (Income) Loss, Net of Tax, Attributable to Noncontrolling Interest Comprehensive income attributable to noncontrolling interest Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive income attributable to Ecolab CONSOLIDATED BALANCE SHEETS Assets [Abstract] ASSETS Assets, Current [Abstract] Current assets Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents Accounts Receivable, Net, Current Accounts receivable, net Total Inventory, Net Inventories Total Other Assets, Current Other current assets Total Assets, Current Total current assets Property, Plant and Equipment, Net Property, plant and equipment, net Total Goodwill Ending goodwill Beginning goodwill Goodwill Intangible Assets, Net (Excluding Goodwill) Other intangible assets, net Total Operating Lease, Right-of-Use Asset Operating lease assets Other Assets, Noncurrent Other assets Total Assets Total assets Liabilities and Equity [Abstract] LIABILITIES AND EQUITY Liabilities, Current [Abstract] Current liabilities Debt, Current Short-term debt Short-term debt including current maturities of long-term debt Accounts Payable, Current Accounts payable Employee-related Liabilities, Current Compensation and benefits Accrued Income Taxes, Current Income taxes Other Liabilities, Current Other current liabilities Total Liabilities, Current Total current liabilities Long-term Debt and Capital Lease Obligations Long-term debt Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent Pension and postretirement benefits Deferred Income Tax Liabilities, Net Deferred income taxes Present value of lessee's discounted obligation for lease payments from operating lease, classified as noncurrent and excluded from long-term debt obligations. Operating Lease Liability Noncurrent, Excluded From Long-term Debt Operating lease liabilities Other Liabilities, Noncurrent Other liabilities Liabilities Total liabilities Commitments and Contingencies. Commitments and contingencies (Note 16) Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Equity (a) Common Stock, Value, Issued Common stock Additional Paid in Capital, Common Stock Additional paid-in capital Retained Earnings (Accumulated Deficit) Retained earnings Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive loss Total Treasury Stock, Value Treasury stock Stockholders' Equity Attributable to Parent Total Ecolab shareholders' equity Stockholders' Equity Attributable to Noncontrolling Interest Noncontrolling interest Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Balance, Ending Balance, beginning Total equity Liabilities and Equity Total liabilities and equity N/A Common Stock Shares Issued Not Disclosed Common Stock, Shares Authorized Common stock, shares authorized Common Stock, Par or Stated Value Per Share Common stock, par value per share (in dollars per share) Common Stock, Shares, Outstanding Balance, Ending (in shares) Balance, beginning (in shares) Common stock, shares outstanding CONSOLIDATED STATEMENTS OF CASH FLOWS Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] OPERATING ACTIVITIES Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to cash provided by operating activities: Depreciation Depreciation Amortization Amortization Deferred Income Taxes and Tax Credits Deferred income taxes Share-based Compensation Share-based compensation expense Pension and Other Postretirement Benefit Contributions Pension and postretirement plan contributions Pension and Other Postretirement Benefit Expense Pension and postretirement plan (income) expense, net Restructuring Costs Restructuring charges, net of cash paid Gain (Loss) on Disposition of Business Sale of global surgical solutions business Other Noncash Income (Expense) Other, net Increase (Decrease) in Operating Capital [Abstract] Changes in operating assets and liabilities, net of effect of acquisitions: Increase (Decrease) in Accounts Receivable Accounts receivable Increase (Decrease) in Inventories Inventories Increase (Decrease) in Other Operating Assets Other assets Increase (Decrease) in Accounts Payable Accounts payable Increase (Decrease) in Other Operating Liabilities Other liabilities Net Cash Provided by (Used in) Operating Activities Cash provided by operating activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] INVESTING ACTIVITIES Payments to Acquire Property, Plant, and Equipment Capital expenditures Proceeds from Sale of Productive Assets Property and other assets sold Proceeds from Divestiture of Businesses, Net of Cash Divested Divestiture of businesses, net of cash divested Payments for (Proceeds from) Other Investing Activities Other, net Net Cash Provided by (Used in) Investing Activities Cash used for investing activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] FINANCING ACTIVITIES Proceeds from (Repayments of) Short-term Debt Net issuances of commercial paper and notes payable Proceeds from Issuance of Long-term Debt Long-term debt borrowings Payments for Repurchase of Common Stock Reacquired shares Payments of Ordinary Dividends, Common Stock Dividends paid Proceeds from Stock Options Exercised Exercise of employee stock options Proceeds from (Payments for) Other Financing Activities Other, net Net Cash Provided by (Used in) Financing Activities Cash used for financing activities Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Effect of exchange rate changes on cash and cash equivalents Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect, Continuing Operations Decrease in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Including Disposal Group and Discontinued Operations Cash and cash equivalents, end of period Cash and cash equivalents, beginning of period CONSOLIDATED STATEMENTS OF EQUITY Equity Components [Axis] Equity Component [Domain] TOTAL ECOLAB SHAREHOLDERS' EQUITY Ecolab Shareholders' Equity COMMON STOCK Common Stock ADDITIONAL PAID-IN CAPITAL Additional Paid-in Capital RETAINED EARNINGS Retained Earnings ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) AOCI (Loss) TREASURY STOCK Treasury Stock NON-CONTROLLING INTEREST Non-Controlling Interest Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity Dividends, Common Stock, Cash Cash dividends declared (a) Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Stock options and awards Treasury Stock, Value, Acquired, Cost Method Reacquired shares Treasury Stock, Shares, Acquired Reacquired shares (in shares) Reacquired shares (in shares) Common Stock, Dividends, Per Share, Declared Dividends declared per common share (in dollars per share) CONSOLIDATED FINANCIAL INFORMATION Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] CONSOLIDATED FINANCIAL INFORMATION No definition available. SPECIAL (GAINS) AND CHARGES The aggregate amount of other nonrecurring expenses, not previously categorized, that are infrequent in occurrence or unusual in nature. Special Gains and Charges [Text Block] SPECIAL (GAINS) AND CHARGES ACQUISITIONS Business Combination Disclosure [Text Block] ACQUISITIONS BALANCE SHEETS INFORMATION Supplemental Balance Sheet Disclosures [Text Block] BALANCE SHEETS INFORMATION DEBT AND INTEREST Debt Disclosure [Text Block] DEBT AND INTEREST GOODWILL AND OTHER INTANGIBLE ASSETS Goodwill and Intangible Assets Disclosure [Text Block] GOODWILL AND OTHER INTANGIBLE ASSETS FAIR VALUE MEASUREMENTS Fair Value Disclosures [Text Block] FAIR VALUE MEASUREMENTS DERIVATIVES AND HEDGING TRANSACTIONS Derivative Instruments and Hedging Activities Disclosure [Text Block] DERIVATIVES AND HEDGING TRANSACTIONS OTHER COMPREHENSIVE INCOME (LOSS) INFORMATION Comprehensive Income (Loss) Note [Text Block] OTHER COMPREHENSIVE INCOME (LOSS) INFORMATION SHAREHOLDERS' EQUITY Stockholders' Equity Note Disclosure [Text Block] SHAREHOLDERS' EQUITY EARNINGS ATTRIBUTABLE TO ECOLAB PER COMMON SHARE ("EPS") Earnings Per Share [Text Block] EARNINGS ATTRIBUTABLE TO ECOLAB PER COMMON SHARE ("EPS") INCOME TAXES Income Tax Disclosure [Text Block] INCOME TAXES PENSION AND POSTRETIREMENT PLANS Pension and Other Postretirement Benefits Disclosure [Text Block] PENSION AND POSTRETIREMENT PLANS REVENUES Revenue from Contract with Customer [Text Block] REVENUES