v3.26.1
Note 1 - Description of Business and Summary of Significant Accounting Policies - Basic and Diluted Net Earnings Per Common Share (Details) - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Net earnings attributable to Bel shareholders $ 61,536 $ 40,960 $ 73,831
Undistributed earnings 58,071 37,521 70,322
Common Class A [Member]      
Net earnings attributable to Bel shareholders 9,837 6,572 11,830
Less dividends declared 508 508 512
Undistributed earnings $ 9,329 $ 6,064 $ 11,318
Weighted-average shares outstanding, basic (in shares) 2,115 2,124 2,142
Net earnings per share, basic (in dollars per share) $ 4.65 $ 3.1 $ 5.52
Common Class B [Member]      
Net earnings attributable to Bel shareholders $ 51,699 $ 34,388 $ 62,001
Less dividends declared 2,957 2,931 2,997
Undistributed earnings $ 48,742 $ 31,457 $ 59,004
Weighted-average shares outstanding, basic (in shares) 10,525 10,491 10,634
Weighted-average shares outstanding, diluted (in shares) 10,546 10,491 10,634
Net earnings per share, basic (in dollars per share) $ 4.91 $ 3.28 $ 5.83
Net earnings per share, diluted (in dollars per share) $ 4.9 $ 3.28 $ 5.83