v3.25.3

Asset Retirement Obligation (Details) $ in Millions	9 Months Ended		12 Months Ended
Asset Retirement Obligation (Details) $ in Millions	Sep. 30, 2025 USD ($)	Sep. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)	Mar. 07, 2024 USD ($)	Dec. 31, 2023 USD ($)	Jul. 27, 2018 USD ($)
ARO Loss Contingencies [Line Items]
Asset Retirement Obligation, Liabilities Incurred	$ 16.2		$ 29.8
Number Of Consent Decrees	2
Asset Retirement Obligation	$ 2,538.9		2,572.2		$ 2,213.4
Surety Bonds Outstanding Delivered To EPA				$ 327.1
Asset retirement obligations	$ 2,253.7		2,219.4
Number Of Decades Remaining For Trust	3
Asset Retirement Obligation, Liabilities Settled	$ (217.2)		(253.8)
Accretion expense for asset retirement obligations	97.5	$ 80.9	111.2
Asset Retirement Obligation, Revision of Estimate	70.0		541.4
Asset Retirement Obligation, Foreign Currency Translation Gain (Loss)	40.1		(69.8)
Asset Retirement Obligation, Reclass to Held for Sale	(39.9)		0.0
Asset retirement obligations	285.2		352.8
Unfavorable Regulatory Action \| 2015 Consent Decrees With EPA
ARO Loss Contingencies [Line Items]
Asset retirement obligations, undiscounted			2,300.0
Asset Retirement Obligation			1,100.0
Bonnie Facility Trust [Member]
ARO Loss Contingencies [Line Items]
Assets Held-in-trust, Current						$ 21.0
Plant City and Bonnie Facilities
ARO Loss Contingencies [Line Items]
Asset retirement obligations	$ 342.5		$ 368.7

Asset Retirement Obligation, Reclass to Held for Sale

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Number Of Consent Decrees

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Number Of Decades Remaining For Trust

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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.

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Undiscounted amount of the accrual for environmental loss contingencies.

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The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

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Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.

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Current portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

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Amount of foreign currency translation gain (loss) which decreases (increases) asset retirement obligations.

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Amount of asset retirement obligations incurred during the period.

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Amount of asset retirement obligations settled, or otherwise disposed of, during the period. This may include asset retirement obligations transferred to third parties associated with the sale of a long-lived asset.

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Amount of increase (decrease) in the asset retirement obligation from changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation.

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Noncurrent portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

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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 within one year of the balance sheet date (or operating cycle, if longer) at which time the assets held-in-trust will be released or forfeited.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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MOSAIC CO 10-Q