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Related Party Agreements (Narrative) (Details) |  |  |  |  |  |  |  | 3 Months Ended | 9 Months Ended | 12 Months Ended
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Jan. 02, 2024 shares | Jan. 01, 2024 shares | Jan. 01, 2023 shares | Jan. 01, 2017 USD ($) shares | Jul. 26, 2016 USD ($) shares | Jul. 22, 2016 | Mar. 13, 2015 | Sep. 30, 2024 USD ($) | Sep. 30, 2023 USD ($) | Sep. 30, 2024 USD ($) shares | Sep. 30, 2023 USD ($) | Dec. 31, 2023 USD ($) item shares | Dec. 31, 2022 USD ($) shares
Related Party Agreements |  |  |  |  |  |  |  |  |  |  |  |  |
Shares issued for services (in shares) | shares |  |  | 3,742 |  |  |  |  |  |  |  |  |  |
Preferred stock voting rights multiplier |  |  |  |  | 1.1 |  |  |  |  |  |  |  |
Proceeds from debt issuance |  |  |  |  |  |  |  |  |  |  |  | $ 0 | $ 30,000,000
Research and development for licenses acquired |  |  |  |  |  |  |  |  |  |  |  | 527,000 | 1,474,000
General and administrative |  |  |  |  |  |  |  | $ 1,400,000 | $ 2,131,000 | $ 4,358,000 | $ 7,507,000 | $ 9,686,000 | $ 12,210,000
Unvested restricted stock awards |  |  |  |  |  |  |  |  |  |  |  |  |
Related Party Agreements |  |  |  |  |  |  |  |  |  |  |  |  |
Number of shares issued | shares |  |  |  |  |  |  |  |  |  |  |  | 720 | 475
Class A Preferred Shares |  |  |  |  |  |  |  |  |  |  |  |  |
Related Party Agreements |  |  |  |  |  |  |  |  |  |  |  |  |
Shares issuable on conversion, per share converted | shares |  |  |  |  | 1 |  |  |  |  |  |  |  |
Fortress Biotech, Inc |  |  |  |  |  |  |  |  |  |  |  |  |
Related Party Agreements |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from related party debt |  |  |  |  | $ 2,000,000 |  |  |  |  |  |  |  |
Percentage of annual fees expense related to Management Services Agreement recorded in research and development expenses |  |  |  |  |  |  |  |  |  |  |  | 50.00% |
Percentage of annual fees expense related to Management Services Agreement recorded in general and administrative expenses |  |  |  |  |  |  |  |  |  |  |  | 50.00% |
Shares issued for services (in shares) | shares | 7,061 | 7,061 |  |  |  |  |  |  |  |  |  | 1,319 | 259
Percentage of fully diluted equity |  | 2.50% | 2.50% |  |  |  |  |  |  |  |  | 2.50% | 2.50%
Expenses from related party transaction |  |  |  |  |  |  |  |  |  |  |  | $ 1,000,000 | $ 500,000
Issuance of common shares (in shares) | shares |  |  |  |  |  |  |  |  |  |  |  |  | 259
Founders agreement term |  |  |  |  | 15 years |  |  |  |  |  |  |  |
Agreement renewal term |  |  |  |  | 1 year |  |  |  |  |  |  |  |
Paid in kind dividend, period prior to payment date for measuring ownership |  |  |  |  | 1 day |  |  |  |  |  |  |  |
Equity fee, period for payment after financing |  |  |  |  |  |  |  |  |  |  |  | 5 days |
Equity fee payable in shares (as a percent) |  |  |  |  |  |  |  |  |  |  |  | (2.50%) |
Cash fee (as a percent) |  |  |  |  |  |  |  |  |  |  |  | (4.50%) |
Cash fee, period for payment |  |  |  |  |  |  |  |  |  |  |  | 90 days |
Change in control fee, multiplier | item |  |  |  |  |  |  |  |  |  |  |  | 5 |
Change in control fee, measurement period |  |  |  |  |  |  |  |  |  |  |  | 12 months |
Change in control fee, specified rate component |  |  |  |  |  |  |  |  |  |  |  | 4.50% |
MSA agreement term |  |  |  |  |  |  | 5 years |  |  |  |  |  |
MSA agreement renewal term |  |  |  |  |  |  | 5 years |  |  |  |  |  |
Annual consulting fee |  |  |  |  |  |  |  |  |  |  |  | $ 500,000 |
Consulting fee when net assets exceed threshold |  |  |  |  |  |  |  |  |  |  |  | 1,000,000 |
Net assets threshold |  |  |  |  |  |  |  |  |  |  |  | 100,000,000 |
Stock dividend (as a percent) |  |  |  |  | 2.50% |  |  |  |  |  |  |  |
Research and development for licenses acquired |  |  |  |  |  |  |  |  |  |  |  | 500,000 | $ 1,100,000
Fortress Biotech, Inc | Class A Preferred Shares |  |  |  |  |  |  |  |  |  |  |  |  |
Related Party Agreements |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of fully diluted equity |  |  |  |  |  | 2.50% |  |  |  |  |  |  |
Number of shares issued in conversion | shares |  |  |  |  | 250,000 |  |  |  |  |  |  |  |
Fortress Biotech, Inc | Common shares |  |  |  |  |  |  |  |  |  |  |  |  |
Related Party Agreements |  |  |  |  |  |  |  |  |  |  |  |  |
Number of shares issued in conversion | shares |  |  |  |  | 7,000,000 |  |  |  |  |  |  |  |
License agreements |  |  |  |  |  |  |  |  |  |  |  |  |
Related Party Agreements |  |  |  |  |  |  |  |  |  |  |  |  |
Research and development for licenses acquired |  |  |  |  |  |  |  |  |  |  |  | 527,000 | 1,474,000
Parent Company | Management Services Agreement (MSA) | Fortress Biotech, Inc |  |  |  |  |  |  |  |  |  |  |  |  |
Related Party Agreements |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of annual fees expense related to Management Services Agreement recorded in research and development expenses |  |  |  |  |  |  |  | 50.00% | 50.00% | 50.00% | 50.00% |  |
Percentage of annual fees expense related to Management Services Agreement recorded in general and administrative expenses |  |  |  |  |  |  |  | 50.00% | 50.00% | 50.00% | 50.00% |  |
Expenses from related party transaction |  |  |  |  |  |  |  | $ 100,000 | $ 100,000 | $ 400,000 | $ 400,000 |  |
Parent Company | Founders Agreement | Fortress Biotech, Inc |  |  |  |  |  |  |  |  |  |  |  |  |
Related Party Agreements |  |  |  |  |  |  |  |  |  |  |  |  |
Shares issued for services (in shares) | shares |  |  |  |  |  |  |  |  |  | 12,833 |  |  |
Percentage of fully diluted equity | 2.50% | 2.50% | 2.50% |  |  | 2.50% |  |  |  |  |  |  |
Expenses from related party transaction |  |  |  |  |  |  |  | $ 29,000 | $ 4,000 | $ 200,000 | $ 4,000 |  |
Research and development for licenses acquired |  |  |  |  |  |  |  |  |  |  |  | 500,000 | 1,100,000
General and administrative |  |  |  |  |  |  |  |  |  |  |  | 100,000 | 200,000
Director |  |  |  |  |  |  |  |  |  |  |  |  |
Related Party Agreements |  |  |  |  |  |  |  |  |  |  |  |  |
Expenses from related party transaction |  |  |  |  |  |  |  |  |  |  |  | 100,000 | 100,000
Annual consulting fee |  |  |  |  |  |  |  |  |  |  |  | 50,000 |
Value of shares granted as compensation |  |  |  |  |  |  |  |  |  |  |  | $ 50,000 | $ 50,000
Director | Unvested restricted stock awards |  |  |  |  |  |  |  |  |  |  |  |  |
Related Party Agreements |  |  |  |  |  |  |  |  |  |  |  |  |
Number of shares issued | shares |  |  |  |  |  |  |  |  |  |  |  | 144 | 95
Director | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |
Related Party Agreements |  |  |  |  |  |  |  |  |  |  |  |  |
Value of shares granted as compensation |  |  |  |  |  |  |  |  |  |  |  | $ 50,000 |
Number of shares granted as compensation | shares |  |  |  |  |  |  |  |  |  |  |  | 200 |
Chairman of the Board |  |  |  |  |  |  |  |  |  |  |  |  |
Related Party Agreements |  |  |  |  |  |  |  |  |  |  |  |  |
Expenses from related party transaction |  |  |  |  |  |  |  |  |  |  |  | $ 110,000 | $ 110,000
Annual consulting fee |  |  |  | $ 60,000 |  |  |  |  |  |  |  |  |
Value of shares granted as compensation |  |  |  |  |  |  |  |  |  |  |  | $ 50,000 | $ 50,000
Chairman of the Board | Unvested restricted stock awards |  |  |  |  |  |  |  |  |  |  |  |  |
Related Party Agreements |  |  |  |  |  |  |  |  |  |  |  |  |
Number of shares issued | shares |  |  |  |  |  |  |  |  |  |  |  | 144 | 95
Chairman of the Board | Maximum |  |  |  |  |  |  |  |  |  |  |  |  |
Related Party Agreements |  |  |  |  |  |  |  |  |  |  |  |  |
Value of shares granted as compensation |  |  |  | $ 50,000 |  |  |  |  |  |  |  |  |
Number of shares granted as compensation | shares |  |  |  | 200 |  |  |  |  |  |  |  |  |

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