| Investments in and Advances to Affiliates [Table Text Block] |
| AFFILIATE/CONTROLLED INVESTMENTS* | | VALUE AT
12/31/25 | | | PURCHASE/
MERGER | | | INTEREST | | | SALES/
MATURITY/
EXPIRATION | | | REALIZED
GAIN (LOSS) | | | CHANGE IN APPRECIATION/
DEPRECIATION | | | VALUE
3/31/26 | | | SHARES HELD AT
3/31/26 | |
| Medical Devices | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
| IntraOp Medical Corp. Convertible Note* | | | 600 | | | | — | | | | — | | | | — | | | | — | | | | (303 | ) | | | 297 | | | | 10,961,129 | |
| IntraOp Medical Corp. Convertible Note* | | | 71 | | | | — | | | | — | | | | — | | | | — | | | | (36 | ) | | | 35 | | | | 1,300,000 | |
| IntraOp Medical Corp. Convertible Note* | | | 28 | | | | — | | | | — | | | | — | | | | — | | | | (15 | ) | | | 13 | | | | 500,000 | |
| IntraOp Medical Corp. Convertible Note* | | | 28 | | | | — | | | | — | | | | — | | | | — | | | | (15 | ) | | | 14 | | | | 500,000 | |
| IntraOp Medical Corp. Convertible Note* | | | 41 | | | | — | | | | — | | | | — | | | | — | | | | (21 | ) | | | 20 | | | | 750,000 | |
| IntraOp Medical Corp. Convertible Note* | | | 28 | | | | — | | | | — | | | | — | | | | — | | | | (13 | ) | | | 14 | | | | 500,000 | |
| IntraOp Medical Corp. Convertible Note* | | | 55 | | | | — | | | | — | | | | — | | | | — | | | | (28 | ) | | | 27 | | | | 1,000,000 | |
| IntraOp Medical Corp. Convertible Note* | | | 28 | | | | — | | | | — | | | | — | | | | — | | | | (15 | ) | | | 13 | | | | 500,000 | |
| IntraOp Medical Corp. Convertible Note* | | | 22 | | | | — | | | | — | | | | — | | | | — | | | | (11 | ) | | | 11 | | | | 400,000 | |
| IntraOp Medical Corp. Term Note* | | | 164 | | | | — | | | | — | | | | — | | | | — | | | | (83 | ) | | | 81 | | | | 3,000,000 | |
| IntraOp Medical Corp. Convertible Note* | | | 27 | | | | — | | | | — | | | | — | | | | — | | | | (13 | ) | | | 14 | | | | 500,000 | |
| IntraOp Medical Corp. Convertible Note* | | | 55 | | | | — | | | | — | | | | — | | | | — | | | | (28 | ) | | | 27 | | | | 1,000,000 | |
| IntraOp Medical Corp. Convertible Note* | | | 27 | | | | — | | | | — | | | | — | | | | — | | | | (13 | ) | | | 14 | | | | 500,000 | |
| IntraOp Medical Corp. Convertible Note* | | | 27 | | | | — | | | | — | | | | — | | | | — | | | | (13 | ) | | | 14 | | | | 500,000 | |
| IntraOp Medical Corp. Convertible Note* | | | 55 | | | | — | | | | — | | | | — | | | | — | | | | (28 | ) | | | 27 | | | | 1,000,000 | |
| IntraOp Medical Corp. Convertible Note* | | | 27 | | | | — | | | | — | | | | — | | | | — | | | | (13 | ) | | | 14 | | | | 500,000 | |
| IntraOp Medical Corp. Convertible Note* | | | 27 | | | | — | | | | — | | | | — | | | | — | | | | (13 | ) | | | 14 | | | | 500,000 | |
| IntraOp Medical Corp. Convertible Note* | | | 27 | | | | — | | | | — | | | | — | | | | — | | | | (13 | ) | | | 14 | | | | 500,000 | |
| IntraOp Medical Corp. Convertible Note* | | | 11 | | | | — | | | | — | | | | — | | | | — | | | | (6 | ) | | | 5 | | | | 200,000 | |
| IntraOp Medical Corp. Convertible Note* | | | 38 | | | | — | | | | — | | | | — | | | | — | | | | (19 | ) | | | 19 | | | | 700,000 | |
| IntraOp Medical Corp. Convertible Note* | | | 8 | | | | — | | | | — | | | | — | | | | — | | | | (4 | ) | | | 4 | | | | 150,000 | |
| IntraOp Medical Corp. Convertible Note* | | | 19 | | | | — | | | | — | | | | — | | | | — | | | | (10 | ) | | | 9 | | | | 350,000 | |
| IntraOp Medical Corp. Preferred Stock* | | | 0 | | | | — | | | | — | | | | — | | | | — | | | | — | | | | 0 | | | | 26,856,187 | |
| IntraOp Medical Corp. Term Note* | | | 110 | | | | — | | | | — | | | | — | | | | — | | | | (56 | ) | | | 54 | | | | 2,000,000 | |
| Total Medical Devices | | $ | 1,523 | | | | — | | | $ | — | | | | — | | | | — | | | $ | (769 | ) | | $ | 754 | | | | | |
| Semiconductor Equipment | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
| Revasum, Inc. CDIs*(1) | | | 0 | | | | — | | | | — | | | | — | | | | — | | | | — | | | | 0 | | | | 39,774,889 | |
| Total Semiconductor Equipment | | $ | 0 | | | | — | | | $ | — | | | | — | | | | — | | | $ | — | | | $ | 0 | | | | | |
| Advanced Materials | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
| UCT Coatings, Inc. Common Stock | | | 167,642 | | | | — | | | | — | | | | — | | | | — | | | | (24,082 | ) | | | 143,560 | | | | 1,500,000 | |
| Total Advanced Materials | | $ | 167,642 | | | | — | | | $ | — | | | | — | | | | — | | | $ | (24,082 | ) | | $ | 143,560 | | | | | |
| Automotive | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
| Wrightspeed, Inc. Common Stock* | | | 0 | | | | — | | | | — | | | | — | | | | — | | | | — | | | | 0 | | | | 69,102 | |
| Wrightspeed, Inc. Preferred Stock* | | | 0 | | | | — | | | | — | | | | — | | | | — | | | | — | | | | 0 | | | | 60,733,693 | |
| Total Automotive | | $ | 0 | | | | — | | | $ | — | | | | — | | | | — | | | $ | — | | | $ | 0 | | | | | |
| Total Affiliates and Controlled Investments | | $ | 169,165 | | | | — | | | $ | — | | | | — | | | $ | — | | | $ | (24,851 | ) | | $ | 144,314 | | | | | |
| Total Affiliates | | | 167,642 | | | | — | | | | — | | | | — | | | | — | | | | (24,082 | ) | | | 143,560 | | | | | |
| Total Controlled Investments | | $ | 1,523 | | | | — | | | $ | — | | | | — | | | $ | — | | | $ | (769 | ) | | $ | 754 | | | | | |
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