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v3.22.2.2

Marketable Securities Held in Trusts (Details) $ in Millions | Sep. 30, 2022 USD ($) | Dec. 31, 2021 USD ($) | Aug. 31, 2016 USD ($)
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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 | $ 695.6 | $ 710.3 |
Gross unrealized gains | 0.0 | 12.1 |
Gross unrealized losses | (54.6) | (7.5) |
Debt Securities, Available-for-sale | 641.0 | 714.9 |
Cash and Cash Equivalents | Level 1 |  |  |
Available-for-sale Securities, Fair Value to Amortized Cost Basis |  |  |
Amortized cost | 8.4 | 8.1 |
Gross unrealized gains | 0.0 | 0.0 |
Gross unrealized losses | 0.0 | 0.0 |
Debt Securities, Available-for-sale | 8.4 | 8.1 |
Corporate debt securities | Level 2 |  |  |
Available-for-sale Securities, Fair Value to Amortized Cost Basis |  |  |
Amortized cost | 200.2 | 198.8 |
Gross unrealized gains | 0.0 | 5.6 |
Gross unrealized losses | (20.7) | (0.9) |
Debt Securities, Available-for-sale | 179.5 | 203.5 |
Municipal bonds | Level 2 |  |  |
Available-for-sale Securities, Fair Value to Amortized Cost Basis |  |  |
Amortized cost | 202.1 | 198.1 |
Gross unrealized gains | 0.0 | 6.5 |
Gross unrealized losses | (12.6) | (0.5) |
Debt Securities, Available-for-sale | 189.5 | 204.1 |
U.S. government bonds | Level 2 |  |  |
Available-for-sale Securities, Fair Value to Amortized Cost Basis |  |  |
Amortized cost | 284.7 | 305.3 |
Gross unrealized gains | 0.0 | 0.0 |
Gross unrealized losses | (21.3) | (6.1) |
Debt Securities, Available-for-sale | 263.4 | $ 299.2 |
Debt securities |  |  |
Available-for-sale Securities, Fair Value to Amortized Cost Basis |  |  |
Debt Securities, Available-for-sale | 632.6 |  |
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 |  |

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