Note 2 - Acquisitions - Pro Forma Information (Details) - dataMate [Member] - USD ($) $ / shares in Units, $ in Thousands |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
|
| Revenue, net | $ 220,510 | $ 185,096 | $ 612,012 | $ 514,402 |
| Net earnings | 38,389 | 24,532 | 87,790 | 70,886 |
| Less: Net earnings attributable to non-controlling interest | 276 | 620 | 3,005 | 2,280 |
| Redemption value adjustment attributable to noncontrolling interest | 11,823 | (315) | 21,194 | (1,595) |
| Net earnings attributable to Bel Fuse shareholders | $ 26,290 | $ 24,227 | $ 63,591 | $ 70,201 |
| Common Class A [Member] | ||||
| Earnings per common share - basic (in dollars per share) | $ 1.74 | $ 1.83 | $ 4.48 | $ 5.32 |
| Earnings per common share - diluted (in dollars per share) | 1.74 | 1.83 | 4.48 | 5.32 |
| Common Class B [Member] | ||||
| Earnings per common share - basic (in dollars per share) | 1.84 | 1.93 | 4.72 | 5.6 |
| Earnings per common share - diluted (in dollars per share) | $ 1.83 | $ 1.93 | $ 4.72 | $ 5.6 |
| X | ||||||||||
- Definition The pro forma net Income or Loss attributable to noncontrolling interests for the period as if the business combination or combinations had been completed at the beginning of a period. No definition available.
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- Definition The pro forma net Income or Loss including noncontrolling interests for the period as if the business combination or combinations had been completed at the beginning of a period. No definition available.
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- Definition The pro forma net Income or Loss attributable to redemption value adjustment attributable to noncontrolling interests for the period as if the business combination or combinations had been completed at the beginning of a period. No definition available.
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- Definition Per basic share amount, after tax, of pro forma income (loss) of combined entity as if acquisition date of business combination occurred as of beginning of period. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Per diluted share amount, after tax, of pro forma income (loss) of combined entity as if acquisition date of business combination occurred as of beginning of period. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition Amount, after tax, of pro forma income (loss) of combined entity as if acquisition date of business combination occurred as of beginning of period. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition Amount of pro forma revenue of combined entity as if acquisition date of business combination occurred as of beginning of period. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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