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RELATIONSHIP AND AGREEMENTS WITH SHENGHE - Offtake Agreement and Original Commercial Agreements (Details) - USD ($) $ in Millions |  |  | 1 Months Ended | 18 Months Ended |  |  |
--- | --- | --- | --- | --- | --- | --- | ---
Jun. 05, 2020 | Jun. 20, 2017 | Mar. 31, 2022 | May 31, 2017 | Jun. 30, 2020 | Nov. 16, 2020 | Dec. 31, 2019 | May 22, 2017
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |
Preferred interest percentage held by Shenghe |  |  |  |  |  |  |  | 9.99%
MPMO |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |
Preferred units, outstanding (shares) |  |  |  |  |  | 200.86 | 110.98 |
Offtake Agreement | Affiliated Entity |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |
Initial term |  |  | 2 years |  |  |  |  |
Extension period |  |  | 1 year |  |  |  |  |
Initial Prepayment Amount | Affiliated Entity |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |
Advances |  |  |  | $ 50.0 |  |  |  |
Increase in advances |  | $ 30.0 |  |  |  |  |  |
Initial Prepayment Amount | Affiliated Entity | Shenghe |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |
Increase in advances | $ 30.0 |  |  |  |  |  |  |
First Additional Advance | Affiliated Entity |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |
Advances |  | $ 30.0 |  |  |  |  |  |
Shenghe Implied Discount | Affiliated Entity | Shenghe |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |
Shenghe Implied Discount, percentage of contractual gross profit |  | 36.00% |  |  | 36.00% |  |  |

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