Condensed Consolidated Statements of Shareholders' Equity and Redeemable Noncontrolling Interest (Unaudited) - USD ($) shares in Thousands, $ in Thousands |
Common Class A [Member]
Common Stock [Member]
|
Common Class A [Member]
Retained Earnings [Member]
|
Common Class A [Member] |
Common Class B [Member]
Common Stock [Member]
|
Common Class B [Member]
Additional Paid-in Capital [Member]
|
Common Class B [Member]
Retained Earnings [Member]
|
Common Class B [Member] |
Additional Paid-in Capital [Member] |
Retained Earnings [Member] |
AOCI Attributable to Parent [Member] |
Noncontrolling Interest [Member] |
Total |
| Balance at Dec. 31, 2024 |
$ 212
|
|
|
$ 1,046
|
|
|
|
$ 31,514
|
$ 345,031
|
$ (17,227)
|
$ 80,586
|
$ 360,576
|
| Balance (in shares) at Dec. 31, 2024 |
2,115
|
|
|
10,425
|
|
|
|
|
|
|
|
|
| Net earnings attributable to Bel Fuse shareholders |
|
|
|
|
|
|
|
|
17,874
|
|
838
|
17,874
|
| Cash dividends declared on common stock |
|
$ (127)
|
$ (127)
|
|
|
$ (737)
|
$ (737)
|
|
|
|
|
|
| Issuance of restricted common stock |
|
|
|
$ 13
|
|
|
|
(13)
|
|
|
|
0
|
| Issuance of restricted common stock (in shares) |
|
|
|
129
|
|
|
|
|
|
|
|
|
| Forfeiture of restricted common stock |
|
|
|
$ (2)
|
|
|
|
|
|
|
|
0
|
| Foreign currency translation adjustment, net of taxes |
|
|
|
|
|
|
|
|
|
(1,248)
|
|
(1,248)
|
| Unrealized losses on interest rate swap cash flow hedge, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
(588)
|
|
(588)
|
| Stock-based compensation expense |
|
|
|
|
|
|
|
1,179
|
|
|
|
1,179
|
| Change in unfunded SERP liability, net of taxes |
|
|
|
|
|
|
|
|
|
(28)
|
|
(28)
|
| Balance at Mar. 31, 2025 |
$ 212
|
|
|
$ 1,059
|
|
|
|
32,680
|
362,041
|
(19,091)
|
81,034
|
376,901
|
| Balance (in shares) at Mar. 31, 2025 |
2,115
|
|
|
10,552
|
|
|
|
|
|
|
|
|
| Dividends paid to noncontrolling interest holders |
|
|
|
|
|
|
|
|
|
|
(390)
|
|
| Currency translation adjustment, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
(1,248)
|
|
(1,248)
|
| Change in unfunded SERP liability, net of taxes |
|
|
|
|
|
|
|
|
|
(28)
|
|
(28)
|
| Net earnings |
|
|
|
|
|
|
|
|
17,874
|
|
838
|
17,874
|
| Redemption value adjustment attributable to noncontrolling interest |
|
|
|
|
|
|
|
|
|
|
(390)
|
|
| Balance at Dec. 31, 2024 |
$ 212
|
|
|
$ 1,046
|
|
|
|
31,514
|
345,031
|
(17,227)
|
80,586
|
360,576
|
| Balance (in shares) at Dec. 31, 2024 |
2,115
|
|
|
10,425
|
|
|
|
|
|
|
|
|
| Net earnings attributable to Bel Fuse shareholders |
|
|
|
|
|
|
|
|
|
|
|
66,985
|
| Cash dividends declared on common stock |
|
|
(381)
|
|
|
|
(2,218)
|
|
|
|
|
|
| Foreign currency translation adjustment, net of taxes |
|
|
|
|
|
|
|
|
|
|
|
(362)
|
| Unrealized losses on interest rate swap cash flow hedge, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
|
|
(1,419)
|
| Unrealized holding gains on marketable securities, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
|
|
0
|
| Change in unfunded SERP liability, net of taxes |
|
|
|
|
|
|
|
|
|
|
|
(82)
|
| Balance at Sep. 30, 2025 |
$ 212
|
|
|
$ 1,058
|
|
|
|
36,163
|
409,417
|
(19,090)
|
81,271
|
427,760
|
| Balance (in shares) at Sep. 30, 2025 |
2,115
|
|
|
10,547
|
|
|
|
|
|
|
|
|
| Currency translation adjustment, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
|
|
(362)
|
| Change in unfunded SERP liability, net of taxes |
|
|
|
|
|
|
|
|
|
|
|
(82)
|
| Net earnings |
|
|
|
|
|
|
|
|
|
|
|
66,985
|
| Balance at Mar. 31, 2025 |
$ 212
|
|
|
$ 1,059
|
|
|
|
32,680
|
362,041
|
(19,091)
|
81,034
|
376,901
|
| Balance (in shares) at Mar. 31, 2025 |
2,115
|
|
|
10,552
|
|
|
|
|
|
|
|
|
| Net earnings attributable to Bel Fuse shareholders |
|
|
|
|
|
|
|
|
26,861
|
|
822
|
26,861
|
| Cash dividends declared on common stock |
|
(127)
|
(127)
|
|
|
(740)
|
(740)
|
|
|
|
|
|
| Forfeiture of restricted common stock (in shares) |
|
|
|
(3)
|
|
|
|
|
|
|
|
|
| Forfeiture of restricted common stock |
|
|
|
$ (1)
|
|
|
|
|
|
|
|
0
|
| Foreign currency translation adjustment, net of taxes |
|
|
|
|
|
|
|
|
|
540
|
|
540
|
| Unrealized losses on interest rate swap cash flow hedge, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
(386)
|
|
(386)
|
| Stock-based compensation expense |
|
|
|
|
|
|
|
1,721
|
|
|
|
1,721
|
| Change in unfunded SERP liability, net of taxes |
|
|
|
|
|
|
|
|
|
(27)
|
|
(27)
|
| Balance at Jun. 30, 2025 |
$ 212
|
|
|
$ 1,058
|
|
|
|
34,402
|
388,035
|
(18,964)
|
80,966
|
404,743
|
| Balance (in shares) at Jun. 30, 2025 |
2,115
|
|
|
10,549
|
|
|
|
|
|
|
|
|
| Dividends paid to noncontrolling interest holders |
|
|
|
|
|
|
|
|
|
|
(890)
|
|
| Forfeiture of restricted common stock |
|
|
|
|
|
|
|
1
|
|
|
|
|
| Currency translation adjustment, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
540
|
|
540
|
| Change in unfunded SERP liability, net of taxes |
|
|
|
|
|
|
|
|
|
(27)
|
|
(27)
|
| Net earnings |
|
|
|
|
|
|
|
|
26,861
|
|
822
|
26,861
|
| Redemption value adjustment attributable to noncontrolling interest |
|
|
|
|
|
|
|
|
|
|
(890)
|
|
| Redemption value adjustment attributable to noncontrolling interest |
|
|
|
|
|
|
|
|
|
|
315
|
|
| Net earnings attributable to Bel Fuse shareholders |
|
|
|
|
|
|
|
|
22,250
|
|
620
|
22,250
|
| Cash dividends declared on common stock |
|
(127)
|
(127)
|
|
|
(741)
|
(741)
|
|
|
|
|
|
| Forfeiture of restricted common stock (in shares) |
|
|
|
(2)
|
|
|
|
|
|
|
|
|
| Forfeiture of restricted common stock |
|
|
|
|
|
|
|
|
|
|
|
0
|
| Foreign currency translation adjustment, net of taxes |
|
|
|
|
|
|
|
|
|
346
|
|
346
|
| Unrealized losses on interest rate swap cash flow hedge, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
(445)
|
|
(445)
|
| Unrealized holding gains on marketable securities, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
|
|
0
|
| Stock-based compensation expense |
|
|
|
|
|
|
|
1,761
|
|
|
|
1,761
|
| Change in unfunded SERP liability, net of taxes |
|
|
|
|
|
|
|
|
|
(27)
|
|
(27)
|
| Balance at Sep. 30, 2025 |
$ 212
|
|
|
$ 1,058
|
|
|
|
36,163
|
409,417
|
(19,090)
|
81,271
|
427,760
|
| Balance (in shares) at Sep. 30, 2025 |
2,115
|
|
|
10,547
|
|
|
|
|
|
|
|
|
| Currency translation adjustment, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
346
|
|
346
|
| Change in unfunded SERP liability, net of taxes |
|
|
|
|
|
|
|
|
|
(27)
|
|
(27)
|
| Redemption value adjustment attributable to noncontrolling interest |
|
|
|
|
|
|
|
|
|
|
315
|
|
| Net earnings |
|
|
|
|
|
|
|
|
22,250
|
|
620
|
22,250
|
| Redemption value adjustment attributable to noncontrolling interest |
|
|
|
|
|
|
|
|
|
|
(315)
|
|
| Balance at Dec. 31, 2025 |
$ 212
|
|
|
$ 1,058
|
|
|
|
38,315
|
403,102
|
(17,174)
|
93,161
|
425,513
|
| Balance (in shares) at Dec. 31, 2025 |
2,115
|
|
|
10,543
|
|
|
|
|
|
|
|
|
| Redemption value adjustment attributable to noncontrolling interest |
|
|
|
|
|
|
|
|
|
|
2,633
|
|
| Net earnings attributable to Bel Fuse shareholders |
|
|
|
|
|
|
|
|
11,379
|
|
972
|
11,379
|
| Cash dividends declared on common stock |
|
(127)
|
(127)
|
|
|
(736)
|
(736)
|
|
|
|
|
|
| Issuance of restricted common stock |
|
|
|
$ 6
|
|
|
|
(6)
|
|
|
|
0
|
| Issuance of restricted common stock (in shares) |
|
|
|
53
|
|
|
|
|
|
|
|
|
| Forfeiture of restricted common stock (in shares) |
|
|
|
(1)
|
|
|
|
|
|
|
|
|
| Forfeiture of restricted common stock |
|
|
|
|
|
|
|
|
|
|
|
0
|
| Issuance of shares upon vesting of Performance Stock Units (in shares) |
|
|
|
12
|
|
|
|
|
|
|
|
|
| Foreign currency translation adjustment, net of taxes |
|
|
|
|
|
|
|
|
|
1,143
|
|
1,143
|
| Unrealized losses on interest rate swap cash flow hedge, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
(296)
|
|
(296)
|
| Unrealized holding gains on marketable securities, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
(1)
|
|
(1)
|
| Stock-based compensation expense |
|
|
|
|
|
|
|
2,077
|
|
|
|
2,077
|
| Change in unfunded SERP liability, net of taxes |
|
|
|
|
|
|
|
|
|
(10)
|
|
(10)
|
| Balance at Mar. 31, 2026 |
$ 212
|
|
|
$ 1,064
|
|
|
|
40,386
|
413,618
|
(16,338)
|
96,766
|
438,942
|
| Balance (in shares) at Mar. 31, 2026 |
2,115
|
|
|
10,607
|
|
|
|
|
|
|
|
|
| Currency translation adjustment, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
1,143
|
|
1,143
|
| Change in unfunded SERP liability, net of taxes |
|
|
|
|
|
|
|
|
|
(10)
|
|
(10)
|
| Redemption value adjustment attributable to noncontrolling interest |
|
|
|
|
|
|
|
|
|
|
2,633
|
|
| Net earnings |
|
|
|
|
|
|
|
|
11,379
|
|
972
|
11,379
|
| Redemption value adjustment attributable to noncontrolling interest |
|
|
|
|
|
|
|
|
|
|
(2,633)
|
|
| Balance at Dec. 31, 2025 |
$ 212
|
|
|
$ 1,058
|
|
|
|
38,315
|
403,102
|
(17,174)
|
93,161
|
425,513
|
| Balance (in shares) at Dec. 31, 2025 |
2,115
|
|
|
10,543
|
|
|
|
|
|
|
|
|
| Net earnings attributable to Bel Fuse shareholders |
|
|
|
|
|
|
|
|
|
|
|
63,149
|
| Cash dividends declared on common stock |
|
|
(381)
|
|
|
|
(2,342)
|
|
|
|
|
|
| Foreign currency translation adjustment, net of taxes |
|
|
|
|
|
|
|
|
|
|
|
(928)
|
| Unrealized losses on interest rate swap cash flow hedge, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
|
|
(906)
|
| Unrealized holding gains on marketable securities, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
|
|
91
|
| Change in unfunded SERP liability, net of taxes |
|
|
|
|
|
|
|
|
|
|
|
(27)
|
| Balance at Sep. 30, 2026 |
$ 212
|
|
|
$ 1,236
|
|
|
|
487,339
|
463,528
|
(18,944)
|
0
|
933,371
|
| Balance (in shares) at Sep. 30, 2026 |
2,115
|
|
|
12,325
|
|
|
|
|
|
|
|
|
| Currency translation adjustment, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
|
|
(928)
|
| Change in unfunded SERP liability, net of taxes |
|
|
|
|
|
|
|
|
|
|
|
(27)
|
| Net earnings |
|
|
|
|
|
|
|
|
|
|
|
63,149
|
| Balance at Mar. 31, 2026 |
$ 212
|
|
|
$ 1,064
|
|
|
|
40,386
|
413,618
|
(16,338)
|
96,766
|
438,942
|
| Balance (in shares) at Mar. 31, 2026 |
2,115
|
|
|
10,607
|
|
|
|
|
|
|
|
|
| Redemption value adjustment attributable to noncontrolling interest |
|
|
|
|
|
|
|
|
|
|
6,738
|
|
| Net earnings attributable to Bel Fuse shareholders |
|
|
|
|
|
|
|
|
25,480
|
|
1,757
|
25,480
|
| Cash dividends declared on common stock |
|
(127)
|
(127)
|
|
|
(743)
|
(743)
|
|
|
|
|
|
| Forfeiture of restricted common stock (in shares) |
|
|
|
(8)
|
|
|
|
|
|
|
|
|
| Forfeiture of restricted common stock |
|
|
|
$ (1)
|
|
|
|
|
|
|
|
0
|
| Foreign currency translation adjustment, net of taxes |
|
|
|
|
|
|
|
|
|
1,954
|
|
1,954
|
| Unrealized losses on interest rate swap cash flow hedge, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
(239)
|
|
(239)
|
| Unrealized holding gains on marketable securities, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
34
|
|
34
|
| Stock-based compensation expense |
|
|
|
|
|
|
|
3,034
|
|
|
|
3,034
|
| Change in unfunded SERP liability, net of taxes |
|
|
|
|
|
|
|
|
|
(8)
|
|
(8)
|
| Balance at Jun. 30, 2026 |
$ 212
|
|
|
$ 1,236
|
|
|
|
484,292
|
438,228
|
(14,597)
|
102,601
|
909,371
|
| Balance (in shares) at Jun. 30, 2026 |
2,115
|
|
|
12,324
|
|
|
|
|
|
|
|
|
| Dividends paid to noncontrolling interest holders |
|
|
|
|
|
|
|
|
|
|
(2,660)
|
|
| Issuance of common stock |
|
|
|
$ 173
|
$ 440,871
|
|
441,044
|
|
|
|
|
|
| Issuance of common stock (in shares) |
|
|
|
1,725
|
|
|
|
|
|
|
|
|
| Forfeiture of restricted common stock |
|
|
|
|
|
|
|
1
|
|
|
|
|
| Currency translation adjustment, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
1,954
|
|
1,954
|
| Change in unfunded SERP liability, net of taxes |
|
|
|
|
|
|
|
|
|
(8)
|
|
(8)
|
| Redemption value adjustment attributable to noncontrolling interest |
|
|
|
|
|
|
|
|
|
|
6,738
|
|
| Net earnings |
|
|
|
|
|
|
|
|
25,480
|
|
1,757
|
25,480
|
| Redemption value adjustment attributable to noncontrolling interest |
|
|
|
|
|
|
|
|
|
|
(2,660)
|
|
| Redemption value adjustment attributable to noncontrolling interest |
|
|
|
|
|
|
|
|
|
|
(6,738)
|
|
| Redemption value adjustment attributable to noncontrolling interest |
|
|
|
|
|
|
|
|
|
|
11,823
|
|
| Net earnings attributable to Bel Fuse shareholders |
|
|
|
|
|
|
|
|
26,290
|
|
276
|
26,290
|
| Cash dividends declared on common stock |
|
$ (127)
|
$ (127)
|
|
|
$ (863)
|
(863)
|
|
|
|
|
|
| Forfeiture of restricted common stock (in shares) |
|
|
|
(2)
|
|
|
|
|
|
|
|
|
| Forfeiture of restricted common stock |
|
|
|
$ (1)
|
|
|
|
|
|
|
|
(1)
|
| Foreign currency translation adjustment, net of taxes |
|
|
|
|
|
|
|
|
|
(4,025)
|
|
(4,025)
|
| Unrealized losses on interest rate swap cash flow hedge, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
(371)
|
|
(371)
|
| Unrealized holding gains on marketable securities, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
58
|
|
58
|
| Stock-based compensation expense |
|
|
|
|
|
|
|
3,047
|
|
|
|
3,047
|
| Change in unfunded SERP liability, net of taxes |
|
|
|
|
|
|
|
|
|
(9)
|
|
(9)
|
| Balance at Sep. 30, 2026 |
$ 212
|
|
|
$ 1,236
|
|
|
|
$ 487,339
|
463,528
|
(18,944)
|
0
|
933,371
|
| Balance (in shares) at Sep. 30, 2026 |
2,115
|
|
|
12,325
|
|
|
|
|
|
|
|
|
| Dividends paid to noncontrolling interest holders |
|
|
|
|
|
|
|
|
|
|
(662)
|
|
| Issuance of common stock |
|
|
|
$ 1
|
|
|
$ 1
|
|
|
|
|
|
| Issuance of common stock (in shares) |
|
|
|
3
|
|
|
|
|
|
|
|
|
| Currency translation adjustment, net of taxes of $0 in all periods presented |
|
|
|
|
|
|
|
|
|
(4,025)
|
|
(4,025)
|
| Change in unfunded SERP liability, net of taxes |
|
|
|
|
|
|
|
|
|
$ (9)
|
|
(9)
|
| Redemption value adjustment attributable to noncontrolling interest |
|
|
|
|
|
|
|
|
|
|
11,823
|
|
| Net earnings |
|
|
|
|
|
|
|
|
$ 26,290
|
|
276
|
$ 26,290
|
| Transfer of redeemable noncontrolling interest |
|
|
|
|
|
|
|
|
|
|
(114,038)
|
|
| Redemption value adjustment attributable to noncontrolling interest |
|
|
|
|
|
|
|
|
|
|
(662)
|
|
| Redemption value adjustment attributable to noncontrolling interest |
|
|
|
|
|
|
|
|
|
|
$ (11,823)
|
|