Cover $ in Billions	12 Months Ended
Cover $ in Billions	Dec. 31, 2025 USD ($) shares
Cover [Abstract]
Document Type	10-K/A
Document Annual Report	true
Document Period End Date	Dec. 31, 2025
Document Transition Report	false
Entity File Number	001-32327
Registrant Name	Mosaic Co
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-1026454
Entity Address, Address Line One	101 East Kennedy Blvd
Entity Address, Address Line Two	Suite 2500
Entity Address, City or Town	Tampa
Entity Address, State or Province	FL
Entity Address, Postal Zip Code	33602
City Area Code	800
Local Phone Number	918-8270
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	MOS
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float \| $	$ 11.5
Entity Common Stock, Shares Outstanding \| shares	317,505,258
Current Fiscal Year End Date	--12-31
Central Index Key	0001285785
Amendment Flag	true
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	FY
Amendment Description	The Mosaic Company (the “Company”), a corporation incorporated under the State of Delaware, originally filed its Annual Report on Form 10-K for the year ended December 31, 2025 with the Securities and Exchange Commission (the “SEC”) on February 27, 2026 (the “Original Form 10-K”). This Amendment No. 1 on Form 10-K/A (the “Amendment”) is being filed solely to: (i) provide the disclosure in Part II, Item 5 regarding the number of shareholders of record outstanding as of February 20, 2026 which was inadvertently omitted from the Original Form 10-K; and (ii) file a revised Esterhazy Potash Facility Consent of Qualified Persons, included as Exhibit 23.5 to this Amendment. This filing includes Part II, Item 5 with the addition of the information regarding the number of shareholders of record outstanding as of February 20, 2026, and Part IV, Item 15, which includes the revised Esterhazy Potash Facility Consent of Qualified Persons. In addition, as required by Rule 12b‑15, this Amendment includes the certifications of the Company’s principal executive and financial officers required by Rule 13a‑14(a). Because this Amendment does not include financial statements, the Company has not provided new certifications under Rule 13a-14(b).Except as explicitly set forth herein, this Amendment does not otherwise change, modify or update any other disclosures, or exhibits to, the Original Form 10-K. This Amendment speaks as of the filing date of the Original Form 10-K and does not reflect facts or events that may have occurred subsequent to the filing date of the Original Form 10-K.

MOSAIC CO 10-K/A