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FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Thousands | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | ---
Financial assets: |  |
Cash and cash equivalents | $ 136,627 | $ 1,179,297
Level 1 |  |
Financial assets: |  |
Cash and cash equivalents | 136,627 | 1,179,297
Short-term investments | 1,045,718 |
Restricted cash | 6,882 | 1,860
Level 2 |  |
Financial assets: |  |
Cash and cash equivalents | 0 | 0
Short-term investments | 0 |
Restricted cash | 0 | 0
Level 3 |  |
Financial assets: |  |
Cash and cash equivalents | 0 | 0
Short-term investments | 0 |
Restricted cash | 0 | 0
Convertible Notes | Level 1 |  |
Financial liabilities: |  |
Debt fair value | 610,650 | 880,026
Convertible Notes | Level 2 |  |
Financial liabilities: |  |
Debt fair value | 0 | 0
Convertible Notes | Level 3 |  |
Financial liabilities: |  |
Debt fair value | 0 | 0
Offtake Advances | Level 1 |  |
Financial liabilities: |  |
Debt fair value |  | 0
Offtake Advances | Level 2 |  |
Financial liabilities: |  |
Debt fair value |  | 0
Offtake Advances | Level 3 |  |
Financial liabilities: |  |
Debt fair value |  | 16,501
Equipment notes | Level 1 |  |
Financial liabilities: |  |
Debt fair value | 0 | 0
Equipment notes | Level 2 |  |
Financial liabilities: |  |
Debt fair value | 6,807 | 9,737
Equipment notes | Level 3 |  |
Financial liabilities: |  |
Debt fair value | 0 | 0
Carrying Amount |  |
Financial assets: |  |
Cash and cash equivalents | 136,627 | 1,179,297
Short-term investments | 1,045,718 |
Restricted cash | 6,882 | 1,860
Carrying Amount | Convertible Notes |  |
Financial liabilities: |  |
Debt fair value | 678,444 | 674,927
Carrying Amount | Offtake Advances |  |
Financial liabilities: |  |
Debt fair value |  | 16,082
Carrying Amount | Equipment notes |  |
Financial liabilities: |  |
Debt fair value | 7,135 | 9,661
Fair Value |  |
Financial assets: |  |
Cash and cash equivalents | 136,627 | 1,179,297
Short-term investments | 1,045,718 |
Restricted cash | 6,882 | 1,860
Fair Value | Convertible Notes |  |
Financial liabilities: |  |
Debt fair value | 610,650 | 880,026
Fair Value | Offtake Advances |  |
Financial liabilities: |  |
Debt fair value |  | 16,501
Fair Value | Equipment notes |  |
Financial liabilities: |  |
Debt fair value | $ 6,807 | $ 9,737

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