Maximum Maximum [Member] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Net (loss) gain on marketable securities held in trust fund, net of tax OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment, Tax Statistical Measurement [Domain] Statistical Measurement [Domain] Cloud computing cost Cloud computing asset Cloud computing asset Income Tax Jurisdiction, Domestic Federal Income Tax Jurisdiction, Domestic Federal [Member] Short-term Debt, Type [Axis] Short-Term Debt, Type [Axis] Title of each class Title of 12(b) Security Reported Value Measurement Reported Value Measurement [Member] Interest And Penalties [Abstract] Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued [Abstract] Schedule of Available-for-sale Securities [Table] Debt Securities, Available-for-Sale [Table] Document Fiscal Year Focus Document Fiscal Year Focus Debt, Weighted Average Interest Rate Debt, Weighted Average Interest Rate Financial Instrument [Axis] Financial Instrument [Axis] Segment Reporting [Abstract] Segment Reporting [Abstract] Common stock, par value Common Stock, Value, Issued Payroll and employee benefits Employee-related Liabilities, Current Other Other Assets, Miscellaneous, Noncurrent Loss Contingency Accrual Loss Contingency Accrual Available-for-sale Securities, Fair Value to Amortized Cost Basis Debt Securities, Available-for-Sale, Fair Value to Amortized Cost, after Allowance for Credit Loss [Abstract] Inventory Write-down Inventory Write-down Brazilian Non Income Tax Proceedings Brazilian Non Income Tax Proceedings [Member] Brazilian judicial and administrative proceedings relating to various non-income tax matters. APIC, Share-based Payment Arrangement, Restricted Stock Unit, Increase for Cost Recognition APIC, Share-Based Payment Arrangement, Restricted Stock Unit, Increase for Cost Recognition Derivative Instrument [Axis] Derivative Instrument [Axis] Measurement Frequency [Axis] Measurement Frequency [Axis] U.S. government bonds US Treasury and Government [Member] Change in unrecognized tax benefit Unrecognized Tax Benefits, Period Increase (Decrease) Amendment flag Amendment Flag Goodwill [Line Items] Goodwill [Line Items] Current liabilities: Liabilities, Current [Abstract] Consolidated Entities [Axis] Consolidated Entities [Axis] Canadian resource taxes Canadian Resource Taxes Canadian resource tax expense consisting of provincial taxes on potash production and a resource surcharge based on the value of resource sales from Saskatchewan mines. Entity common stock shares outstanding Entity Common Stock, Shares Outstanding MRO inventory Inventory, Noncurrent AOCI, Derivative Qualifying as Hedge, Excluded Component, Noncontrolling Interest [Member] AOCI, Derivative Qualifying as Hedge, Excluded Component, Parent [Member] Gross unrealized losses Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax ARO Loss Contingencies [Table] Loss Contingencies [Table] Loss Contingencies [Table] Long-Lived Asset, Impairment and Disposal [Abstract] Cash Flows from Operating Activities Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract] Other comprehensive income (loss), net of tax Other Comprehensive Income (Loss), Net of Tax [Abstract] Repayments of inventory financing arrangement Repayments of inventory financing arrangement Repayments of inventory financing arrangement Deferred and other income taxes Increase (Decrease) in Deferred Income Taxes Related Party Transactions Disclosure Related Party Transactions Disclosure [Text Block] Consolidated Entities [Domain] Consolidated Entities [Domain] Asset Retirement Obligation, Liabilities Settled Asset Retirement Obligation, Liabilities Settled State Entity Address, State or Province Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss [Abstract] Common stock, par value Common Stock, Par or Stated Value Per Share Foreign currency translation gain Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Capital expenditures Segment Reporting, Long-Lived Asset, Expenditure for Addition Contract Termination Costs Contract Termination Costs Contract Termination Costs Derivative, Notional Amount Derivative, Notional Amount Basic weighted average number of shares outstanding Weighted Average Number of Shares Outstanding, Basic Schedule of related party transactions Schedule of Related Party Transactions [Table Text Block] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Asset Retirement Obligation Asset Retirement Obligation ARO Loss Contingencies [Line Items] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Number of Reportable Segments Number of Reportable Segments Total current liabilities Liabilities, Current Subsegments Consolidation Items [Axis] Subsegments Consolidation Items [Axis] Work in process Inventory, Work in Process, Net of Reserves Accelerated Depreciation Accelerated Depreciation Accelerated Depreciation Available-for-sale debt maturities, after 5 but within 10 years, fair value Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Schedule Of Derivative Instruments Notional Amounts Schedule of Derivative Instruments [Table Text Block] Short-term Debt, Type [Domain] Short-Term Debt, Type [Domain] City Entity Address, City or Town Equity securities Equity Method Investments, Fair Value Disclosure Commercial Paper Commercial Paper Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Plant City and Bonnie Facilities Plant City and Bonnie Facilities [Member] Plant City and Bonnie Facilities [Member] Assets held for sale Disposal Group, Including Discontinued Operation, Assets Derivative, Nonmonetary Notional Amount Derivative, Nonmonetary Notional Amount Accounts and Other Receivables, Net, Current Accounts and Other Receivables, Net, Current Level 2 Fair Value, Inputs, Level 2 [Member] Other comprehensive income Other Comprehensive Income (Loss), Net of Tax Long-Term Debt, Current Maturities Long-Term Debt, Current Maturities United States UNITED STATES Stock Issued During Period, Shares, Restricted Stock Award, Gross Stock Issued During Period, Shares, Restricted Stock Award, Gross Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax Receivable Purchasing Arrangements Sold Receivable Purchasing Arrangements Sold Accounts receivable sold under an agreement with a bank Number Of Decades Remaining For Trust Number Of Decades Remaining For Trust Number Of Decades Remaining For Trust Litigation Case [Axis] Litigation Case [Axis] Schedule of Segment Reporting Information Segment Reporting [Table Text Block] Noncontrolling Interest Noncontrolling Interest [Member] Gain (Loss) on Disposition of Stock in Subsidiary or Equity Method Investee Gain (Loss) on Disposition of Stock in Subsidiary or Equity Method Investee Municipal bonds Municipal Bonds [Member] Accounting Estimates Use of Estimates, Policy [Policy Text Block] Impairment of Long-Lived Assets to be Disposed of Impairment of Long-Lived Assets to be Disposed of Other Comprehensive Income (Loss), Tax Other Comprehensive Income (Loss), before Tax Available-for-sale debt maturities, after 1 but within 5 years, fair value Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five Document period end date Document Period End Date Performance Products Product Type Four [Member] A fourth major group of related products sold by the entity. Net cash used in investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Disposal Group, Including Discontinued Operation, Liabilities, Current Disposal Group, Including Discontinued Operation, Liabilities, Current Preferred stock, outstanding Preferred Stock, Shares Outstanding Name of each exchange on which registered Security Exchange Name Debt Securities, Available-for-sale, Realized Loss Debt Securities, Available-for-Sale, Realized Loss Long-Lived Asset, Held-for-Sale, Fair Value Disclosure Long-Lived Asset, Held-for-Sale, Fair Value Disclosure Tax Credit Carryforward [Table] Tax Credit Carryforward [Table] Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Entity shell company Entity Shell Company Number of Interest Rate Derivatives Held Number of Interest Rate Derivatives Held Operating lease obligation Operating Lease, Liability, Current Surety Bonds Outstanding Delivered To EPA Surety Bonds Outstanding Delivered To EPA The face amount of surety bonds provided by the entity as of the balance sheet date, which were issued to provide assurance to EPA in connection with mining reclamation obligations. Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Restricted cash Restricted Cash Equivalent, Noncurrent Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), after Adjustments, Tax Earnings Per Share Earnings Per Share [Text Block] Earnings Per Share [Abstract] Earnings Per Share [Abstract] Document Fiscal Period Focus Document Fiscal Period Focus Trading symbol Trading Symbol Financing Arrangements [Abstract] Financing Arrangements [Abstract] Financing Arrangements [Abstract] Geographical [Domain] Geographical [Domain] Capital expenditures Payments to Acquire Property, Plant, and Equipment Brazilian subsidiary judicial and administrative proceedings Brazilian subsidiary judicial and administrative proceedings [Member] Brazilian subsidiary judicial and administrative proceedings Accrued income and other taxes Accrued Income Taxes, Current Purchases of available-for-sale securities - restricted Payments to Acquire Debt Securities, Available-for-Sale Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Canpotex Canpotex [Member] The export association of the Saskatchewan potash producers. Unrealized (gain) loss on derivatives Unrealized Gain (Loss) on Derivatives Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Long-Term Debt, Gross Long-Term Debt, Gross Payments of structured accounts payable arrangements Repayments of Bank Debt Asset Retirement Obligation, Reclass to Held for Sale Asset Retirement Obligation, Reclass to Held for Sale Asset Retirement Obligation, Reclass to Held for Sale Inventory Financing Arrangement, Maximum Amount Inventory Financing Arrangement, Maximum Amount Inventory Financing Arrangement, Maximum Amount Debt securities Debt Securities [Member] Related Party Transactions [Abstract] Related Party Transactions [Abstract] Diluted weighted average number of shares outstanding Diluted weighted average number of shares outstanding Weighted Average Number of Shares Outstanding, Diluted Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Dividends per share Common Stock, Dividends, Per Share, Cash Paid Emerging growth company Entity Emerging Growth Company Related Party Transaction [Line Items] Related Party Transaction [Line Items] Accrued pension and postretirement benefits Liability, Defined Benefit Plan, Noncurrent Disposal Group Name [Domain] Disposal Group Name [Domain] Commercial Paper Commercial Paper [Member] Accounting for Derivative Instruments and Hedging Activities Derivative Instruments and Hedging Activities Disclosure [Text Block] Araxa and Carlsbad Araxa and Carlsbad [Member] Araxa and Carlsbad Accrued dividends Dividends Payable 2015 Consent Decrees With EPA 2015 Consent Decrees With EPA [Member] 2015 Consent Decrees With EPA [Member] Unfavorable Regulatory Action Unfavorable Regulatory Action [Member] Gross liability position Derivative Liability, Subject to Master Netting Arrangement, before Offset Tax Credit Carryforward, Name [Domain] Tax Credit Carryforward, Name [Domain] Mosaic Fertilizantes Mosaic Fertilizantes [Member] Mosaic Fertilizantes Gross margin Gross margin Gross Profit Amounts due to related parties Other Receivables Corporate, Eliminations and Other Corporate Eliminations And Other Segment [Member] Corporate and other non-operating segment activity including intersegment eliminations. Goodwill Goodwill [Text Block] Long-Lived Asset, Held and Used, Impairment Loss Long-Lived Asset, Held and Used, Impairment Loss Long-Lived Asset, Held-for-Sale Long-Lived Asset, Held-for-Sale [Table Text Block] Intangible Asset, Goodwill and Other [Abstract] Intangible Asset, Goodwill and Other [Abstract] Public Utilities, Property, Plant and Equipment, Net Public Utilities, Property, Plant and Equipment, Net Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-Sale [Line Items] Severance Costs Severance Costs Stock based compensation APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Restricted cash in other current assets Restricted Cash Equivalent, Current Level 1 Fair Value, Inputs, Level 1 [Member] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Asset Retirement Obligation, Liabilities Incurred Asset Retirement Obligation, Liabilities Incurred Potash Potash Segment [Member] Potash segment of business. Dilutive impact of share-based awards Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax Phosphate Crop Nutrients Product Type One [Member] A major group of related products sold by the entity. Preferred stock, par value Preferred Stock, Par or Stated Value Per Share Long-term debt, including current portion Long-Term Debt, Fair Value Deferred Tax and Other Liabilities, Noncurrent Deferred Tax and Other Liabilities, Noncurrent Scenario [Domain] Scenario [Domain] Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract] Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation [Abstract] Gross margin (excluding Canadian resource taxes) Gross Profit Excluding Canadian Resource Taxes Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity, excluding Canadian resource taxes. Accounts payable Accounts Payable, Fair Value Disclosure Schedule of Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Debt Disclosure [Abstract] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Current maturities of long-term debt Long-Term Debt and Lease Obligation, Current Segment Reporting Segment Reporting [Text Block] Marketable Securities Held in Trusts Investment in Debt and Equity Securities and Other Trading Assets [Text Block] Minimum Minimum [Member] Cash dividends paid Payments of Ordinary Dividends, Common Stock Disaggregation of Revenue by Product Type Disaggregation of Revenue [Table Text Block] Increase (Decrease) in Asset Retirement Obligations Increase (Decrease) in Asset Retirement Obligations Effect of Exchange Rate on Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Effect of Exchange Rate on Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Cash and cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Total equity Beginning balance Ending balance Equity, Including Portion Attributable to Noncontrolling Interest Affiliated Entity Affiliated Entity [Member] Maximum potential liabilitiy Loss Contingency, Estimate of Possible Loss Derivative [Table] Derivative [Table] Common stock, authorized Common Stock, Shares Authorized Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] New Wales Phase II West Stack New Wales Phase II West Stack [Member] New Wales Phase II West Stack Debt Securities, Available-for-sale, Realized Gain Debt Securities, Available-for-Sale, Realized Gain Asset Retirement Obligation Disclosure [Abstract] Asset Retirement Obligation Disclosure [Abstract] Available-for-sale debt maturities, after 10 years, fair value Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 10 Cash Flows from Investing Activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Related Party Transaction [Axis] Related Party Transaction [Axis] Fair Value, Recurring Fair Value, Recurring [Member] Long-Lived Asset, Held-for-Sale [Line Items] Long-Lived Asset, Held-for-Sale [Line Items] Document quarterly report Document Quarterly Report Amount deposited by Mosaic into the RCRA Trusts Asset, Held-in-Trust, Noncurrent Segments [Domain] Segments [Domain] Accrued liabilities Accrued Liabilities, Current [Abstract] Interest Rate Swap Interest Rate Swap [Member] Patrocinio Patrocinio [Member] Patrocinio Proceeds from sale of available-for-sale securities - restricted Proceeds from Sale of Debt Securities, Available-for-Sale Earnings (loss) from consolidated companies before income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Debt Disclosure Debt Disclosure [Text Block] Payments of long-term debt Repayments of Long-Term Debt Scenario [Axis] Scenario [Axis] Accounts receivable Receivables, Fair Value Disclosure Loss Contingency [Abstract] Loss Contingency [Abstract] Equity securities and investments in nonconsolidated companies Equity Method Investments Equity Component [Domain] Equity Component [Domain] Foreign currency derivatives Foreign Exchange Contract [Member] Duration, Number of Days Duration, Number of Days Duration, Number of Days Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity Debt Securities, Available-for-Sale, Fair Value, Fiscal Year Maturity [Abstract] Assets Held for Sale and Idle Facilities Assets Held for Sale and Idle Facilities [Text Block] Assets Held for Sale and Idle Facilities Dividends Dividends, Common Stock, Cash Total Mosaic stockholders' equity Total Mosaic stockholders' equity Equity, Attributable to Parent Proceeds from Other Short-term Debt Proceeds from Other Short-Term Debt Assets Assets [Abstract] Commerical Paper Note Program, Maximum Amount Commerical Paper Note Program, Maximum Amount Commerical Paper Note Program, Maximum Amount Amortized cost Debt Securities, Available-for-Sale, Amortized Cost Accounting Policies [Abstract] Accounting Policies [Abstract] Environmental Remediation Site [Axis] Environmental Remediation Site [Axis] Average maturity of foreign currency derivative instruments Derivative, Average Remaining Maturity Proceeds from (Payment for) Other Financing Activity Proceeds from (Payment for) Other Financing Activity Selling, general and administrative expenses Selling, General and Administrative Expense Tax Credit Carryforward [Axis] Tax Credit Carryforward [Axis] Contingencies Commitments and Contingencies Disclosure [Text Block] Shares subject to issuance upon exercise of stock options excluded from the calculation of diluted earnings per share Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Goodwill Goodwill [Table Text Block] Structured accounts payable arrangements Short-Term Bank Loans and Notes Payable Entity central index key Entity Central Index Key Accumulated depreciation Property, Plant, and Equipment, Accumulated Depreciation, Depletion, and Amortization Remaining Average Term, Number of Days Remaining Average Term, Number of Days Remaining Average Term, Number of Days Capital in excess of par value Additional Paid in Capital, Common Stock Net cash provided by operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest Indemnification Agreement Vale S.A. Indemnification Agreement [Member] Liabilities held for sale Disposal Group, Including Discontinued Operation, Liabilities Long-Lived Asset, Held-for-Sale [Table] Long-Lived Asset, Held-for-Sale [Table] Equity: Equity, Attributable to Parent [Abstract] Income Statement [Abstract] Income Statement [Abstract] Document transition report Document Transition Report Phosphate Rock Product Type Five [Member] A fifth major group of related products sold by the entity. Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Deferred income taxes Deferred Income Tax Assets, Net Income Tax (Expense) Benefit, Continuing Operations [Abstract] Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract] Idle Facilities [Axis] Idle Facilities [Axis] Idle Facilities Recently Issued Accounting Guidance [Abstract] Recently Issued Accounting Guidance [Abstract] Recently Issued Accounting Guidance [Abstract] Environmental Loss Contingency, Current, Statement of Financial Position [Extensible Enumeration] Environmental Loss Contingency, Current, Statement of Financial Position [Extensible Enumeration] Other Commitments [Domain] Other Commitments [Domain] Area code City Area Code Environmental Loss Contingency, Noncurrent, Statement of Financial Position [Extensible Enumeration] Environmental Loss Contingency, Noncurrent, Statement of Financial Position [Extensible Enumeration] Accumulated Other Comprehensive Loss AOCI Attributable to Parent [Member] Structured accounts payable arrangements Debt Instrument, Fair Value Disclosure Disaggregation of Revenue by Geography Segment Reporting, Entity-Wide Information Not Provided as Part of Reportable Segment, Geographical Area, Revenue [Table Text Block] Potash Crop Nutrients Product Type Two [Member] A second major group of related products sold by the entity. Finished goods Inventory, Finished Goods, Net of Reserves Marketable securities held in trust Debt Securities, Available-for-Sale, Restricted Balance Sheet Related Disclosures [Abstract] Balance Sheet Related Disclosures [Abstract] Other Other Accrued Liabilities, Noncurrent Statement [Line Items] Statement [Line Items] Total assets Assets Assets Environmental contingency accrual Accrual for Environmental Loss Contingencies Other noncurrent liabilities Other Liabilities, Noncurrent [Abstract] Preferred stock, issued Preferred Stock, Shares Issued Accrued Environmental Loss Contingencies, Current Accrued Environmental Loss Contingencies, Current Gross unrealized gains Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax Other current and noncurrent assets Increase (Decrease) in Other Operating Assets Organization and Nature of Business Nature of Operations [Text Block] Asset Retirement Obligation, Foreign Currency Translation Gain (Loss) Asset Retirement Obligation, Foreign Currency Translation Gain (Loss) Measurement Basis [Axis] Measurement Basis [Axis] Other noncurrent liabilities Total other noncurrent liabilities Other Liabilities, Noncurrent Goodwill Goodwill, net of accumulated amortization Goodwill, net of accumulated amortization Goodwill Other Comprehensive Income (Loss), Securities, Available-for-sale, Tax OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment and Tax Available-for-sale debt maturities due within one year, fair value Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, Year One Operating lease obligation Operating Lease, Liability, Noncurrent Retained Earnings Retained Earnings [Member] Operating Expenses Operating Expenses Asset Retirement Obligation Disclosure Asset Retirement Obligation Disclosure [Text Block] AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member] AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Common stock, outstanding Common stock shares outstanding, beginning balance (in shares) Common stock shares outstanding, ending balance (in shares) Common Stock, Shares, Outstanding Net (loss) gain on marketable securities held in trust fund OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax Disaggregation of Revenue [Abstract] Disaggregation of Revenue [Abstract] Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Corporate debt securities Corporate Debt Securities [Member] Diluted net earnings (loss) per share attributable to Mosaic Earnings Per Share, Diluted Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Entity current reporting status Entity Current Reporting Status Net cash provided by financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Brazilian subsidiary labor claims Brazilian subsidiary labor claims [Member] Brazilian subsidiary labor claims Capitalized interest costs Interest Costs Capitalized Other assets Other Assets, Noncurrent [Abstract] Litigation Case [Domain] Litigation Case [Domain] Adjustments to reconcile net earnings including noncontrolling interests to net cash provided by operating activities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Proceeds from structured accounts payable arrangements Proceeds from Bank Debt Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Cash Flows from Financing Activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Property, plant and equipment, net of accumulated depreciation Property, Plant, and Equipment, after Accumulated Depreciation, Depletion, and Amortization Net sales Revenue from Contract with Customer, Excluding Assessed Tax Required collateral assets to be posted if the credit-risk contingent features of these underlying agreements were triggered Additional Collateral, Aggregate Fair Value Financial Instruments [Domain] Financial Instruments [Domain] Disposal Group, Including Discontinued Operation, Assets, Current Disposal Group, Including Discontinued Operation, Assets, Current China and India China and India distribution operations [Member] China and India distribution operations Inventories Inventory Disclosure [Text Block] Carlsbad Carlsbad [Member] Carlsbad Less: Comprehensive income attributable to noncontrolling interest Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Estimate of Fair Value Measurement Estimate of Fair Value Measurement [Member] Prepaid expenses Prepaid Expense, Current Transactions with non-consolidated companies included in cost of sales Related Parties Amount in Cost of Sales Tax Credit Carryforward [Line Items] Tax Credit Carryforward [Line Items] Other Payment for (Proceeds from) Other Investing Activity Inventories Increase (Decrease) in Inventories Proceeds From Inventory Financing Arrangements Proceeds From Inventory Financing Arrangements Proceeds From Inventory Financing Arrangements Idle Facilities [Domain] Idle Facilities [Domain] Idle Facilities [Domain] Segment Reporting [Table] Segment Reporting [Table] Schedule of Related Party Transactions, by Related Party [Table] Related Party Transaction [Table] Other current assets Total other current assets Other Assets, Current Collections from Factoring Receivables Collections from Factoring Receivables Collections from factoring receivables treated as collateralized borrowings, which are classified as financing transactions Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months Term Loan Term Loan [Member] Term Loan Operating earnings (loss) Operating earnings (loss) Operating Income (Loss) Other Product Types Other Product Types [Member] All other products, including animal feed ingredients and industrial potash, that are not separately disclosed. Current fiscal year end date Current Fiscal Year End Date Derivative [Line Items] Derivative [Line Items] Related Party Transaction [Domain] Related Party Transaction [Domain] Entity file number Entity File Number Schedule of maturity dates for debt securities Investments Classified by Contractual Maturity Date [Table Text Block] Common stock, issued Common Stock, Shares, Issued Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract] Accrued Environmental Loss Contingencies, Noncurrent Accrued Environmental Loss Contingencies, Noncurrent Asset retirement obligations Asset Retirement Obligations, Noncurrent Equity in net (earnings) of nonconsolidated companies, net of dividends Income (Loss) from Equity Method Investments, Net of Dividends or Distributions Phosphate Phosphates Segment [Member] Phosphate segment of business. Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Comprehensive Income (Loss) Note [Text Block] Comprehensive Income (Loss) Note [Text Block] Equity Components [Axis] Equity Components [Axis] Product and Service [Domain] Product and Service [Domain] Related Party Related Party [Member] Income taxes (net of refunds) Income Tax Paid, after Refund Received Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Entity interactive data current Entity Interactive Data Current Derivative, Credit Risk Related Contingent Features [Abstract] Derivative, Credit Risk Related Contingent Features [Abstract] Less: Net earnings attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest Deferred income taxes Deferred Income Tax Liabilities, Net Accounts Payable and Accrued Liabilities, Current Accounts Payable and Accrued Liabilities, Current Smaller reporting company Entity Small Business Comprehensive income (loss) attributable to Mosaic Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive Income (Loss), Net of Tax, Attributable to Parent Other Commitments [Axis] Other Commitments [Axis] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Net actuarial (loss) gain and prior service cost Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax Interest expense, net Interest Income (Expense), Operating Unrecognized tax benefits Liability for Uncertainty in Income Taxes, Noncurrent Other assets Total other assets Other Assets, Noncurrent Document type Document Type Unrecognized tax benefits, income tax penalties and interest accrued Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax Accrued liabilities Accrued liabilities Accrued Liabilities, Current Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Brazil BRAZIL Number Of Consent Decrees Number Of Consent Decrees Number Of Consent Decrees Loss on assets to be sold Gain (Loss) on Disposition of Assets Schedule of Goodwill [Table] Goodwill [Table] Other Other Assets, Miscellaneous, Current Cash and Cash Equivalents Cash and Cash Equivalents [Member] Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax Accumulated Other Comprehensive Income (Loss) [Abstract] Accumulated Other Comprehensive Income (Loss) [Abstract] Accumulated Other Comprehensive Income (Loss) [Abstract] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Proceeds from Issuance of Long-Term Debt Proceeds from Issuance of Long-Term Debt Phone number Local Phone Number Canada CANADA Other Financial Statement Data Additional Financial Information Disclosure [Text Block] Zip code Entity Address, Postal Zip Code Entity registrant name Entity Registrant Name Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Changes in assets and liabilities, excluding effects of acquisition: Increase (Decrease) in Operating Assets [Abstract] Payments of Factoring Receivables Repayments of Factoring Receivables Repayments of factoring receivables treated as collateralized borrowings, which are classified as financing transactions. Assets Held-in-trust, Current Asset, Held-in-Trust, Current Net sales Revenues Receivable Purchasing Agreement [Domain] Receivable Purchasing Agreement [Domain] Short-term debt created by the sale of receivables to a third party. Equity in net earnings of nonconsolidated companies Income (Loss) from Equity Method Investments Accounts payable and accrued liabilities Increase (Decrease) in Accounts Payable and Accrued Liabilities Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax Other Comprehensive Income (Loss), Tax Operating materials and supplies Inventory, Supplies, Net of Reserves Liabilities and Equity Liabilities and Equity [Abstract] Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Bonnie Facility Trust [Member] Bonnie Facility Trust [Member] Bonnie Facility Trust Inventories Total Inventory Inventory, Net Inventory Financing Arrangement, Number Of Days Duration Inventory Financing Arrangement, Number Of Days Duration Inventory Financing Arrangement, Number Of Days The aggregate fair value of all derivative instruments with credit-risk-related contingent features that were in a liability position Derivative, Net Liability Position, Aggregate Fair Value Fair Value Measurements Fair Value Disclosures [Text Block] Supplemental Disclosure of Cash Flow Information: Supplemental Cash Flow Information [Abstract] Deferred Proceeds from Sale of Assets Deferred Proceeds from Sale of Assets Deferred Proceeds from Sale of Assets Geographical [Axis] Geographical [Axis] Short-term debt Other Short-Term Borrowings Schedule of Short-term Debt [Table] Short-Term Debt [Table] Other Assets Other Assets Employer identification number Entity Tax Identification Number Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration] Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration] Cash, cash equivalents and restricted cash-beginning of period Cash, cash equivalents and restricted cash-end of period Cash, cash equivalents and restricted cash-end of period Cash, Cash 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Inventory Financing Arrangement Inventory Financing Arrangement [Member] Inventory Financing Arrangement Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract]