Quarterly report [Sections 13 or 15(d)]

Segment Information (Schedule of Segment Information) (Details)

v3.26.1
Segment Information (Schedule of Segment Information) (Details) - USD ($)
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Dec. 31, 2025
Revenue      
Product revenue, net $ 15,921,000 $ 13,139,000  
Other revenue 117,000    
Net revenue 16,038,000 13,139,000  
Operating expenses      
Cost of goods - (excluding amortization of acquired intangible assets) 6,218,000 4,790,000  
Amortization of acquired intangible assets 1,126,000 1,065,000  
Research and development 540,000 3,938,000  
Selling, general and administrative 15,893,000 25,663,000  
Total operating expenses 23,777,000 35,456,000  
Loss from operations (7,739,000) (22,317,000)  
Other income (expense)      
Interest income 570,000 490,000  
Interest expense and financing fee (3,368,000) (2,805,000)  
Gain on sale of priority review voucher, net of expenses 158,873,000    
Change in fair value of partner company derivative liability (7,085,000) 0  
Gain (loss) on common stock warrant liabilities 1,000 (47,000)  
Other income (expense) 1,042,000 (12,000)  
Total other income (expense) 150,033,000 (2,374,000)  
Income (loss) before income tax expense 142,294,000 (24,691,000)  
Income tax expense 5,132,000 0  
Net income (loss) 137,162,000 (24,691,000)  
Attributable to non-controlling interests (26,789,000) 14,107,000  
Net income (loss) attributable to Fortress 110,373,000 (10,584,000)  
Other Significant Items      
Change in fair value of equity method investment accounted for at fair value within other income 1,046,000    
Segment assets 356,874,000 178,071,000 $ 185,548,000
Stock-based compensation - Research & development 23,000 1,343,000  
Stock-based compensation - Selling, general and administrative $ 1,733,000 4,946,000  
Number of reportable segments not disclosed flag true    
Journey      
Revenue      
Product revenue, net $ 15,921,000 13,139,000  
Other revenue 40,000    
Net revenue 15,961,000    
Operating expenses      
Cost of goods - (excluding amortization of acquired intangible assets) 6,218,000 4,790,000  
Amortization of acquired intangible assets 1,126,000 1,065,000  
Research and development   39,000  
Selling, general and administrative 10,109,000 10,569,000  
Total operating expenses 17,453,000 16,463,000  
Loss from operations (1,492,000) (3,324,000)  
Other income (expense)      
Interest income 157,000 149,000  
Interest expense and financing fee (892,000) (891,000)  
Other income (expense) (3,000) (7,000)  
Total other income (expense) (738,000) (749,000)  
Income (loss) before income tax expense (2,230,000)    
Net income (loss) (2,230,000) (4,073,000)  
Other Significant Items      
Segment assets 91,534,000 84,963,000  
Stock-based compensation - Selling, general and administrative 989,000 1,323,000  
Avenue      
Operating expenses      
Research and development 200,000 411,000  
Selling, general and administrative 514,000 1,494,000  
Total operating expenses 714,000 1,905,000  
Loss from operations (714,000) (1,905,000)  
Other income (expense)      
Interest income 18,000 32,000  
Gain (loss) on common stock warrant liabilities 1,000 15,000  
Total other income (expense) 19,000 47,000  
Income (loss) before income tax expense (695,000)    
Net income (loss) (695,000) (1,858,000)  
Other Significant Items      
Segment assets 2,468,000 3,593,000  
Stock-based compensation - Research & development 14,000 40,000  
Stock-based compensation - Selling, general and administrative 47,000 145,000  
Checkpoint      
Operating expenses      
Research and development   3,788,000  
Selling, general and administrative   7,361,000  
Total operating expenses   11,149,000  
Loss from operations   (11,149,000)  
Other income (expense)      
Interest income   1,000  
Gain (loss) on common stock warrant liabilities   (62,000)  
Other income (expense)   (2,000)  
Total other income (expense)   (63,000)  
Net income (loss)   (11,212,000)  
Other Significant Items      
Segment assets   34,165,000  
Stock-based compensation - Research & development   689,000  
Stock-based compensation - Selling, general and administrative   1,267,000  
Mustang      
Operating expenses      
Research and development 178,000 (964,000)  
Selling, general and administrative 880,000 1,217,000  
Total operating expenses 1,058,000 253,000  
Loss from operations (1,058,000) (253,000)  
Other income (expense)      
Interest income 103,000 100,000  
Total other income (expense) 103,000 100,000  
Income (loss) before income tax expense (955,000)    
Net income (loss) (955,000) (153,000)  
Other Significant Items      
Segment assets 16,582,000 14,909,000  
Stock-based compensation - Research & development   (11,000)  
Stock-based compensation - Selling, general and administrative 22,000 50,000  
Fortress      
Revenue      
Other revenue 77,000    
Net revenue 77,000    
Operating expenses      
Research and development 162,000 664,000  
Selling, general and administrative 4,390,000 5,022,000  
Total operating expenses 4,552,000 5,686,000  
Loss from operations (4,475,000) (5,686,000)  
Other income (expense)      
Interest income 292,000 208,000  
Interest expense and financing fee (2,476,000) (1,914,000)  
Gain on sale of priority review voucher, net of expenses 158,873,000    
Change in fair value of partner company derivative liability (7,085,000)    
Other income (expense) 1,045,000 (3,000)  
Total other income (expense) 150,649,000 (1,709,000)  
Income (loss) before income tax expense 146,174,000    
Income tax expense 5,132,000    
Net income (loss) 141,042,000 (7,395,000)  
Other Significant Items      
Change in fair value of equity method investment accounted for at fair value within other income 1,046,000    
Segment assets 246,290,000 40,440,000  
Stock-based compensation - Research & development 9,000 625,000  
Stock-based compensation - Selling, general and administrative 675,000 2,161,000  
Intersegment Activity | Avenue      
Operating expenses      
Research and development 63,000 63,000  
Selling, general and administrative 63,000 117,000  
Intersegment Activity | Checkpoint      
Operating expenses      
Selling, general and administrative   178,000  
Intersegment Activity | Mustang      
Operating expenses      
Research and development 63,000 63,000  
Selling, general and administrative 63,000 279,000  
Intersegment Activity | Fortress      
Operating expenses      
Research and development (126,000) (125,000)  
Selling, general and administrative $ (126,000) $ (573,000)