XML 59 R47.htm IDEA: XBRL DOCUMENT
v3.23.3

Marketable Securities Held in Trusts (Details) $ in Millions | Sep. 30, 2023 USD ($) | Dec. 31, 2022 USD ($) | Aug. 31, 2016 USD ($)
--- | --- | --- | ---
Investments, Debt and Equity Securities [Abstract] |  |  |
Amount deposited by Mosaic into the RCRA Trusts |  |  | $ 630.0
Number Of Decades Remaining For Trust | 3 |  |
Available-for-sale Securities, Fair Value to Amortized Cost Basis |  |  |
Amortized cost | $ (684.3) | $ (678.3) |
Gross unrealized gains | 0.0 | 0.5 |
Gross unrealized losses | (35.3) | (28.7) |
Debt Securities, Available-for-sale | (649.0) | (650.1) |
Cash and Cash Equivalents | Level 1 |  |  |
Available-for-sale Securities, Fair Value to Amortized Cost Basis |  |  |
Amortized cost | (0.2) | (7.7) |
Gross unrealized gains | 0.0 | 0.0 |
Gross unrealized losses | 0.0 | 0.0 |
Debt Securities, Available-for-sale | (0.2) | (7.7) |
Corporate debt securities | Level 2 |  |  |
Available-for-sale Securities, Fair Value to Amortized Cost Basis |  |  |
Amortized cost | (205.1) | (203.8) |
Gross unrealized gains | 0.0 | 0.1 |
Gross unrealized losses | (15.4) | (17.1) |
Debt Securities, Available-for-sale | (189.7) | (186.8) |
Municipal bonds | Level 2 |  |  |
Available-for-sale Securities, Fair Value to Amortized Cost Basis |  |  |
Amortized cost | (207.2) | (197.0) |
Gross unrealized gains | 0.0 | 0.4 |
Gross unrealized losses | (10.8) | (8.0) |
Debt Securities, Available-for-sale | (196.4) | (189.4) |
U.S. government bonds | Level 2 |  |  |
Available-for-sale Securities, Fair Value to Amortized Cost Basis |  |  |
Amortized cost | (272.2) | (269.6) |
Gross unrealized gains | 0.0 | 0.0 |
Gross unrealized losses | (9.1) | (3.6) |
Debt Securities, Available-for-sale | (263.1) | (266.0) |
Debt securities |  |  |
Available-for-sale Securities, Fair Value to Amortized Cost Basis |  |  |
Debt Securities, Available-for-sale | $ (649.2) |  |
Asset-Backed Securities | Level 2 |  |  |
Available-for-sale Securities, Fair Value to Amortized Cost Basis |  |  |
Amortized cost |  | (0.2) |
Gross unrealized gains |  | 0.0 |
Gross unrealized losses |  | 0.0 |
Debt Securities, Available-for-sale |  | $ (0.2) |

X
- Definition Number Of Decades Remaining For Trust + References No definition available. + Details
Name: | mos_NumberOfDecadesRemainingForTrust
Namespace Prefix: | mos_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition The amount of cash, securities, or other assets held by a third-party trustee pursuant to the terms of an agreement which assets are available to be used by beneficiaries to that agreement only within the specific terms thereof and which agreement is expected to terminate more than one year from the balance sheet date (or operating cycle, if longer) at which time the assets held-in-trust will be released or forfeited. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(b)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1 + Details
Name: | us-gaap_AssetsHeldInTrustNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-2 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-2 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(1)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479130/326-30-45-1 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (aa) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481800/320-10-50-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481830/320-10-45-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(6)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479130/326-30-45-1 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesFairValueToAmortizedCostBasisAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CashAndCashEquivalentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_MunicipalBondsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USTreasuryAndGovernmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_DebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |