Accounts payable Accounts Receivable, Net, Current, Total Accounts receivable, net Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance Accumulated other comprehensive loss Payments to Acquire Businesses and Interest in Affiliates, Total Businesses acquired and investments in affiliates, net of cash acquired Payments to Acquire Businesses, Net of Cash Acquired Cash and Cash Equivalents, at Carrying Value, Beginning Balance Cash and cash equivalents Cash and cash equivalents, beginning of period Cash and cash equivalents, end of period Increase (Decrease) in Accounts Receivable Accounts receivable Increase (Decrease) in Inventories, Total Inventories Proceeds from (Repayments of) Short-term Debt, Total Net issuances (repayments) of commercial paper and notes payable Increase (Decrease) in Accounts Payable, Total Accounts payable Commitments and Contingencies Disclosure [Text Block] Commitments and Contingencies Common Stock, Shares Authorized Common stock, shares authorized Common Stock, Shares, Outstanding, Beginning Balance Common stock, shares outstanding Common Stock, Value, Issued, Beginning Balance Common stock Total comprehensive income Comprehensive Income Note [Text Block] Comprehensive Income Cost of Goods and Services Sold, Total Cost of sales (including special charges of $8.0 in 2009) Current liabilities Current liabilities Liabilities, Current, Total Total current liabilities Debt, Current, Total Short-term debt Deferred Income Tax Expense (Benefit), Total Deferred income taxes Business Combination Disclosure [Text Block] Business Acquisitions and Investments Earnings Per Share, Diluted, Total Diluted (in dollars per share) Effect of Exchange Rate on Cash and Cash Equivalents, Total Effect of exchange rate changes on cash Compensation and benefits Share-based Compensation Share-based compensation expense Gain (Loss) on Sale of Property Plant Equipment, Total Gain on sale of plant Gain on sale of businesses Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal INCOME TAXES [Text Block] INCOME TAXES Income taxes Increase (Decrease) in Other Operating Assets Other assets Restructuring Costs, Total Restructuring, net of cash paid Increase (Decrease) in Restricted Cash, Total Deposit into indemnification escrow Inventory, Net, Total Inventories Liabilities and Stockholders' Equity, Total Total liabilities and equity Long-term Debt, Excluding Current Maturities, Total Long-term debt Stockholders' Equity Attributable to Noncontrolling Interest, Beginning Balance Noncontrolling interest Net Cash Provided by (Used in) Financing Activities, Total Cash provided by (used for) financing activities Net Cash Provided by (Used in) Investing Activities, Total Cash used for investing activities Net Cash Provided by (Used in) Operating Activities, Total Cash provided by operating activities Net (repayments) issuances of notes payable Net Income (Loss) Attributable to Parent, Total Net income attributable to Ecolab Net income Cash and Cash Equivalents, Period Increase (Decrease), Total INCREASE IN CASH AND CASH EQUIVALENTS Interest Income (Expense), Net, Total Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Text Block] New Accounting Pronouncements Other Nonrecurring (Income) Expense, Total Special gains and charges Operating Income (Loss), Total Operating income Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Consolidated Financial Information Other, net Pension and postretirement benefits Other Comprehensive Income, Defined Benefit Plans Adjustment, Net of Tax Cumulative translation adjustment Other Comprehensive Income, Foreign Currency Transaction and Translation Adjustment, Net of Tax Minimum pension liability Derivative instruments Other Comprehensive Income, Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Other Assets, Current Other current assets Proceeds from (Payments for) Other Financing Activities Other, net Payments of Dividends, Common Stock Cash dividends on common stock Pension and Other Postretirement Benefit Expense, Total Pension and postretirement plan expense Pension and Other Postretirement Benefits Disclosure [Text Block] Pension and Postretirement Plans Proceeds from Divestiture of Businesses, Net of Cash Divested, Total Sale of businesses Proceeds from Issuance of Long-term Debt, Total Long-term debt borrowings Proceeds from Sale of Property, Plant, and Equipment, Total Property sold Proceeds from sales and maturities of short-term investments Proceeds from Stock Options Exercised Exercise of employee stock options Property, Plant and Equipment, Net, Beginning Balance Property, plant and equipment, net Payments to Acquire Property, Plant, and Equipment, Total Capital expenditures Purchases of short-term investments Related Party Transactions Disclosure [Text Block] RELATED PARTY TRANSACTIONS Repayments of Long-term Debt, Total Long-term debt repayments Payments for Repurchase of Common Stock Reacquired shares Retained Earnings (Accumulated Deficit), Beginning Balance Retained earnings Sales Revenue, Net, Total Net sales Segment Reporting Disclosure [Text Block] Operating Segments Selling, General and Administrative Expense, Total Selling, general and administrative expenses Significant Accounting Policies [Text Block] SIGNIFICANT ACCOUNTING POLICIES CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME AND SHAREHOLDERS' EQUITY SHAREHOLDERS' EQUITY [Text Block] Goodwill and Intangible Assets Disclosure [Text Block] Goodwill and Other Intangible Assets Assets, Current, Total Total current assets TREASURY STOCK Weighted Average Number of Shares Outstanding, Diluted, Total Diluted (in shares) Weighted Average Number of Shares Outstanding, Basic, Total Basic (in shares) COMMON STOCK Assets, Total Total assets Other Liabilities, Current, Total Other current liabilities Other Liabilities, Noncurrent, Total Other liabilities Common Stock, Dividends, Per Share, Declared Dividends declared per common share (in dollars per share) STOCK INCENTIVE AND OPTION PLANS [Text Block] STOCK INCENTIVE AND OPTION PLANS Deferred Tax Assets, Net, Current, Beginning Balance Deferred income taxes RENTALS AND LEASES [Text Block] RENTALS AND LEASES QUARTERLY FINANCIAL DATA (UNAUDITED) [Text Block] QUARTERLY FINANCIAL DATA (UNAUDITED) Treasury Stock, Value, Beginning Balance Treasury stock Cumulative effect adjustment for adoption of SFAS 158 Earnings Per Share, Basic, Total Basic (in dollars per share) Excess Tax Benefit from Share-based Compensation, Financing Activities Excess tax benefits from share-based payment arrangements Excess Tax Benefit from Share-based Compensation, Operating Activities Excess tax benefits from share-based payment arrangements Other Assets, Noncurrent, Total Other assets Increase (Decrease) in Other Operating Liabilities Other liabilities Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Cumulative Effects of Changes in Accounting Principles, Noncontrolling Interest, Total Income before income taxes Common Stock, Par or Stated Value Per Share Common stock, par value per share (in dollars per share) Income before income taxes Stockholders' Equity Attributable to Parent, Beginning Balance Total Ecolab shareholders' equity Income Tax Expense (Benefit), Total Provision for income taxes Pension and Other Postretirement Benefit Contributions, Total Pension and postretirement plan contributions CONSOLIDATED STATEMENT OF CASH FLOWS ADDITIONAL PAID-IN CAPITAL RETAINED EARNINGS ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) Stock options and awards Stock Issued During Period, Value, Share-based Compensation Stock options (in shares) Stock Issued During Period, Shares, Stock Options Exercised Cumulative effect accounting adoption Cumulative Effect of Initial Adoption of FIN 48 Reacquired shares Reacquired shares Treasury Stock, Value, Acquired, Cost Method Special Gains and Charges [Text Block] The aggregate amount of other nonrecurring expenses, not previously categorized, that are infrequent in occurrence or unusual in nature. Special Gains and Charges Balance Sheet Information [Text Block] Disclosure of selected balance sheet information. Selected Balance Sheet Information Interest [Text Block] Disclosure of interest income and interest expense reported during the period. Interest Document and Entity Information Cost of Sales, Special Charges Cost of sales, special charges The aggregate amount of other nonrecurring expenses that are infrequent in occurrence or unusual in nature, included in cost of sales. Goodwill, Beginning Balance Goodwill Earnings Per Share [Text Block] Net Income Attributable to Ecolab Per Common Share Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Total Net income including noncontrolling interest Net income including noncontrolling interest Net income Net Income (Loss) Attributable to Noncontrolling Interest, Total Less: Net income attributable to noncontrolling interest Accrued Income Taxes, Current Income taxes Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Beginning Balance Total equity Balance Balance Accounts Payable, Current Accounts payable Employee-related Liabilities, Current Compensation and benefits Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent Postretirement health care and pension benefits Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities, Other Other, net Payments for Software, Total Capitalized software expenditures CONSOLIDATED STATEMENT OF INCOME Statement Net income attributable to Ecolab per common share. Net income attributable to Ecolab per common share ASSETS Current assets LIABILITIES AND EQUITY Statement [Table] OPERATING ACTIVITIES Adjustments to reconcile net income including noncontrolling interest to cash provided by operating activities: Changes in operating assets and liabilities: INVESTING ACTIVITIES FINANCING ACTIVITIES CONSOLIDATED STATEMENT OF CASH FLOWS CONSOLIDATED BALANCE SHEET Weighted-average common shares outstanding Interest Expense, Net Interest expense, net 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. Fair Value Disclosures Derivatives and Hedging Activities Disclosure [Text Block] Financial Instruments and Hedging Transactions This element reflects the entity's entire fair value of financial instruments and derivative instruments and hedging activities disclosure as a single block of text. Describes an entity's risk management strategies, derivatives in hedging activities and non-hedging derivative instruments, the assets, obligations, liabilities, revenues and expenses arising there from, and the amounts of and methodologies and assumptions used in determining the amounts of such items. Provides disclosure regarding the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments, assets, and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the Company is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risk is are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information. SUPPLEMENTAL CASH FLOW INFORMATION Operating expenses Impairment of Investments Business write-downs and closures Statement, Equity Components [Axis] Equity Component [Domain] TOTAL ECOLAB SHAREHOLDERS' EQUITY NON-CONTROLLING INTEREST COMPREHENSIVE INCOME. COMPREHENSIVE INCOME Increase (Decrease) in Stockholders' Equity Unrealized gains (losses) on securities Other Comprehensive Income, Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax Total comprehensive income Comprehensive Income, Net of Tax, Including Portion Attributable to Noncontrolling Interest Distributions to noncontrolling interests Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Purchase of shares from noncontrolling interest Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests Initial investment by noncontrolling interest Noncontrolling Interest, Increase from Stock Issuance or Sale of Parent Equity Interest Treasury Stock, Shares, Acquired Reacquired shares (in shares) Balance (in shares) Balance (in shares) Shares, Issued Stockholders' Equity, Period Increase (Decrease) Stock Issued During Period, Shares, Period Increase (Decrease) Dividends, Common Stock, Cash Cash dividends declared Stock Issued During Period, Shares, Share-based Compensation Stock awards, net issuances (in shares) Business Acquisitions and Dispositions Description of business acquisitions and dispositions for the period. Business Acquisitions and Dispositions [Text Block] Stockholders' Equity, Policy [Text Block] SHAREHOLDERS' EQUITY RESEARCH EXPENDITURES Description and amounts of research expenditures for the period. Research Expenditures [Text Block] Finite-Lived Intangible Assets, Net Other intangible assets, net Additional Paid in Capital, Common Stock Additional paid-in capital Equity (a) Depreciation, Depletion and Amortization Depreciation and amortization Income Taxes Paid Income taxes paid Interest Paid Interest paid Allowance for Doubtful Accounts Receivable, Current Accounts receivable, allowance (in dollars) Special Gains and Charges Selected Balance Sheet Information Interest Financial Instruments and Hedging Transactions Comprehensive Income Business Acquisitions and Investments Net Income Attributable to Ecolab Per Common Share Pension and Postretirement Plans Operating Segments Goodwill and Other Intangible Assets New Accounting Pronouncements Commitments and Contingencies SIGNIFICANT ACCOUNTING POLICIES RELATED PARTY TRANSACTIONS Business Acquisitions and Dispositions SHAREHOLDERS' EQUITY STOCK INCENTIVE AND OPTION PLANS INCOME TAXES RENTALS AND LEASES RESEARCH EXPENDITURES QUARTERLY FINANCIAL DATA (UNAUDITED) Consolidated Financial Information