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Significant Accounting Policies (Details) € in Millions | 1 Months Ended | 3 Months Ended | 6 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | ---
Sep. 30, 2023 EUR (€) | Jun. 30, 2025 USD ($) | Jun. 30, 2024 USD ($) | Jun. 30, 2025 USD ($) | Jun. 30, 2024 USD ($) | Dec. 31, 2024 USD ($) | Dec. 31, 2023 USD ($) | Dec. 31, 2023 EUR (€) | Dec. 31, 2020 USD ($)
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |
General and administrative expense |  | $ 4,006,000 | $ 8,546,000 | $ 8,360,000 | $ 13,298,000 | $ 33,281,000 | $ 18,757,000 |  |
Research and development |  | 690,000 | 971,000 | $ 1,615,000 | 1,384,000 | $ 6,245,000 | 9,632,000 |  |
Reportable segment |  |  |  | 1 |  | 1 |  |  |
Impairment |  |  |  | $ 0 | 0 |  |  |  |
Deferred transaction costs |  | 139,000 |  | 139,000 |  |  | 16,234,000 |  |
Impairment charges |  | 0 |  | 0 |  |  |  |  |
Contract asset |  | 0 |  | 0 |  | 0 |  |  |
Deferred revenue |  | 100,000 |  | 100,000 |  | 0 |  |  |
Sales and marketing expense |  | 183,000 | 62,000 | 303,000 | 123,000 | 1,989,000 | 866,000 |  |
Minimum purchase commitments |  |  |  |  |  |  |  |  |
Termination fee (in Euro) | € | € 0.3 |  |  |  |  |  |  | € 0.3 |
Commercial sales and total revenue |  | 1,302,000 | 56,000 | 1,473,000 | 75,000 | 1,373,000 | 3,441,000 |  |
Accounts receivable |  |  |  |  |  | 900,000 | 0 |  |
Inventory balance |  | 346,000 |  | 346,000 |  | 1,760,000 | 235,000 |  |
Contract assets |  |  |  |  |  | 0 | 0 |  |
Stock-based compensation expense |  | $ 1,563,000 | $ 97,000 | $ 3,694,000 | $ 195,000 | $ 18,164,000 | 643,000 |  |
Discontinued Operations, Disposed of by Means Other than Sale, Abandonment [Member] | Discontinued Production Of Mylo [Member] |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |
Impairment charges |  |  |  |  |  |  | 10,200,000 |  |
Discontinued Operations, Disposed of by Means Other than Sale, Abandonment [Member] | Research And Development Operations In California [Member] |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |
Impairment charges |  |  |  |  |  |  | $ 9,100,000 |  |
Customer Concentration Risk [Member] | Customer One [Member] | Revenue Benchmark [Member] |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |
Total revenue |  | 95.00% | 98.00% | 94.00% | 72.00% | 88.00% | 99.00% | 99.00% |
Restricted Stock Units (RSUs) [Member] |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |
Stock-based compensation expense |  | $ 1,400,000 |  | $ 3,300,000 |  | $ 17,000,000 | $ 0 |  |
Non-US | Geographic Concentration Risk | Net Assets, Geographic Area |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |
Total revenue |  |  |  | 1.00% |  | 1.00% |  |  |
Correction of Error [Member] |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |
General and administrative expense |  |  |  |  | $ 1,100,000 |  | 2,600,000 |  |
Research and development |  |  |  |  | $ (1,100,000) |  | 2,000,000 |  |
Sales and marketing expense |  |  |  |  |  |  | $ 600,000 |  |

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