Bel Fuse (BELFB) 10-Q 10 May 21 2021 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2021	May 01, 2021
Document Information [Line Items]
Entity Central Index Key	0000729580
Entity Registrant Name	BEL FUSE INC /NJ
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q1
Document Fiscal Year Focus	2021
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	000-11676
Entity Address, Address Line One	206 Van Vorst Street
Entity Address, City or Town	Jersey City
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	07302
City Area Code	201
Local Phone Number	432-0463
Entity Incorporation, State or Country Code	NJ
Entity Tax Identification Number	22-1463699
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Common Class B [Member]
Document Information [Line Items]
Title of 12(b) Security	Class B Common Stock ($0.10 par value)
Trading Symbol	BELFB
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		10,197,602
Common Class A [Member]
Document Information [Line Items]
Title of 12(b) Security	Class A Common Stock ($0.10 par value)
Trading Symbol	BELFA
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		2,144,912

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current Assets:
Cash and cash equivalents	$ 74,040	$ 84,939
Accounts receivable, net of allowance for doubtful accounts of $819 and $1,036, respectively	74,070	71,372
Inventories	106,737	100,133
Unbilled receivables	12,868	14,135
Assets held for sale	1,635	0
Other current assets	10,010	9,637
Total current assets	279,360	280,216
Property, plant and equipment, net	37,865	34,501
Right-of-use assets	12,615	14,217
Intangible assets, net	64,319	65,789
Goodwill	26,623	23,966
Deferred income taxes	5,774	5,705
Other assets	29,868	29,472
Total assets	456,424	453,866
Current Liabilities:
Accounts payable	42,452	39,774
Accrued expenses	29,176	28,476
Current portion of long-term debt	6,779	5,286
Operating lease liabilities, current	6,409	6,591
Other current liabilities	6,157	7,409
Total current liabilities	90,973	87,536
Long-term Liabilities:
Long-term debt	107,472	110,294
Operating lease liabilities, long-term	6,532	8,064
Liability for uncertain tax positions	28,737	26,089
Minimum pension obligation and unfunded pension liability	24,807	24,620
Deferred income taxes	1,144	1,030
Other liabilities	10,436	10,434
Total liabilities	270,101	268,067
Commitments and contingencies
Stockholders' Equity:
Preferred stock, no par value, 1,000,000 shares authorized; none issued	0	0
Additional paid-in capital	36,737	36,136
Retained earnings	168,846	166,491
Accumulated other comprehensive loss	(20,494)	(18,063)
Total stockholders' equity	186,323	185,799
Total liabilities and stockholders' equity	456,424	453,866
Common Class A [Member]
Stockholders' Equity:
Common stock	214	214
Common Class B [Member]
Stockholders' Equity:
Common stock	$ 1,020	$ 1,021

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Accounts receivable, allowance for doubtful accounts	$ 819	$ 1,036
Preferred stock, no par value (in dollars per share)	$ 0	$ 0
Preferred stock, shares authorized (in shares)	1,000,000	1,000,000
Preferred stock, shares issued (in shares)	0	0
Common Class A [Member]
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, shares authorized (in shares)	10,000,000	10,000,000
Common stock, shares outstanding (in shares)	2,144,912	2,144,912
Common stock, treasury shares (in shares)	1,072,769	1,072,769
Common Class B [Member]
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, shares authorized (in shares)	30,000,000	30,000,000
Common stock, shares outstanding (in shares)	10,200,602	10,208,602
Common stock, treasury shares (in shares)	3,218,307	3,218,307

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue	$ 110,643	$ 103,978
Cost of sales	86,384	78,220
Gross profit	24,259	25,758
Research and development costs	4,986	6,059
Selling, general and administrative expenses	20,995	20,690
Restructuring charges	0	128
Gain on sale of property	(6,175)	0
Income (loss) from operations	4,453	(1,119)
Interest expense	(801)	(1,351)
Other income (expense), net	546	(2,106)
Earnings (loss) before provision for (benefit from) income taxes	4,198	(4,576)
Provision for (benefit from) income taxes	999	(772)
Net earnings (loss) available to common stockholders	3,199	(3,804)
Common Class A [Member]
Net earnings (loss) available to common stockholders	$ 522	$ (649)
Net earnings (loss) per common share:
Common shares - basic and diluted (in dollars per share)	$ 0.24	$ (0.30)
Weighted-average number of shares outstanding:
Common shares - basic and diluted (in shares)	2,145	2,145
Common Class B [Member]
Net earnings (loss) available to common stockholders	$ 2,677	$ (3,155)
Net earnings (loss) per common share:
Common shares - basic and diluted (in dollars per share)	$ 0.26	$ (0.31)
Weighted-average number of shares outstanding:
Common shares - basic and diluted (in shares)	10,203	10,123

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Net earnings (loss) available to common stockholders	$ 3,199	$ (3,804)
Other comprehensive income (loss):
Currency translation adjustment, net of taxes of $9 in the three months ended March 31, 2021 and ($27) in the three months ended March 31, 2020	(2,529)	(2,245)
Unrealized losses on marketable securities arising during the period, net of taxes of $0 in the three months ended March 31, 2021	(1)	0
Change in unfunded SERP liability, net of taxes of ($28) in the three months ended March 31, 2021 and ($20) in the three months ended March 31, 2020	99	66
Other comprehensive loss	(2,431)	(2,179)
Comprehensive income (loss)	$ 768	$ (5,983)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) (Parentheticals) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Foreign currency translation adjustment, tax expense	$ 9
Unrealized loss on marketable securities arising during the period, tax	0
Change in unfunded SERP liability, tax	$ (28)

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Common Class A [Member]Retained Earnings [Member]	Common Class A [Member]AOCI Attributable to Parent [Member]	Common Class A [Member]Common Stock, Common Class A [Member]	Common Class A [Member]Common Stock, Common Class B [Member]	Common Class A [Member]Additional Paid-in Capital [Member]	Common Class A [Member]	Common Class B [Member]Retained Earnings [Member]	Common Class B [Member]AOCI Attributable to Parent [Member]	Common Class B [Member]Common Stock, Common Class A [Member]	Common Class B [Member]Common Stock, Common Class B [Member]	Common Class B [Member]Additional Paid-in Capital [Member]	Common Class B [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Common Stock, Common Class A [Member]	Common Stock, Common Class B [Member]	Additional Paid-in Capital [Member]	Total
Balance at Dec. 31, 2019													$ 157,063	$ (24,065)	$ 214	$ 1,013	$ 33,826	$ 168,051
Net earnings (loss) available to common stockholders						$ (649)						$ (3,155)	(3,804)	0	0	0	0	(3,804)
Cash dividends declared on common stock	$ (130)	$ 0	$ 0	$ 0	$ 0	(130)	$ (709)	$ 0	$ 0	$ 0	$ 0	(709)
Forfeiture of restricted common stock													0	0	0	(1)		0
Forfeiture of restricted common stock, APIC																	1
Foreign currency translation adjustment, net of taxes of $9													0	(2,245)	0	0	0	(2,245)
Unrealized losses on marketable securities arising during the period, net of taxes of $0 in the three months ended March 31, 2021																		0
Stock-based compensation expense													0	0	0	0	603	603
Change in unfunded SERP liability, net of taxes of ($28)													0	66	0	0	0	66
Balance at Mar. 31, 2020													152,420	(26,244)	214	1,012	34,430	161,832
Balance at Dec. 31, 2020													166,491	(18,063)	214	1,021	36,136	185,799
Net earnings (loss) available to common stockholders						522						2,677	3,199	0	0	0	0	3,199
Cash dividends declared on common stock	$ (128)	$ 0	$ 0	$ 0	$ 0	$ (128)	$ (716)	$ 0	$ 0	$ 0	$ 0	$ (716)
Forfeiture of restricted common stock													0	0	0	(1)		0
Forfeiture of restricted common stock, APIC																	1
Foreign currency translation adjustment, net of taxes of $9													0	(2,529)	0	0	0	(2,529)
Unrealized losses on marketable securities arising during the period, net of taxes of $0 in the three months ended March 31, 2021														(1)				(1)
Stock-based compensation expense													0	0	0	0	600	600
Change in unfunded SERP liability, net of taxes of ($28)													0	99	0	0	0	99
Balance at Mar. 31, 2021													$ 168,846	$ (20,494)	$ 214	$ 1,020	$ 36,737	$ 186,323

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) (Parentheticals) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Common Class A [Member]
Dividends declared (in dollars per share)	$ 0.06	$ 0.06
Common Class B [Member]
Dividends declared (in dollars per share)	$ 0.07	$ 0.07
Foreign currency translation adjustment, tax expense	$ 9	$ (27)
Change in unfunded SERP liability, tax	(28)	(20)
Foreign currency translation adjustment, tax expense	9	(27)
Change in unfunded SERP liability, tax	$ (28)	$ (20)

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Cash Flows (Unaudited) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)	Mar. 31, 2020USD ($)
Cash flows from operating activities:
Net earnings (loss)	$ 3,199	$ (3,804)
Adjustments to reconcile net earnings (loss) to net cash provided by operating activities:
Depreciation and amortization	4,145	4,126
Stock-based compensation	600	603
Amortization of deferred financing costs	165	149
Deferred income taxes	48	(1,322)
Net unrealized gains on foreign currency revaluation	(361)	(45)
Gain on sale of property	(6,175)	0
Other, net	(941)	(215)
Changes in operating assets and liabilities:
Accounts receivable, net	174	6,682
Unbilled receivables	1,267	2,721
Inventories	(1,293)	2,059
Accounts payable	804	(4,891)
Accrued expenses	(263)	(2,884)
Other operating assets/liabilities, net	397	4,879
Net cash provided by operating activities	1,766	8,058
Cash flows from investing activities:
Purchases of property, plant and equipment	(1,203)	(1,832)
Payments for acquisitions, net of cash acquired	(14,759)	0
Proceeds from disposal/sale of property, plant and equipment	6,724	2
Net cash used in investing activities	(9,238)	(1,830)
Cash flows from financing activities:
Dividends paid to common stockholders	(815)	(806)
Deferred financing costs	0	(600)
Repayments of long-term debt	(1,487)	(8,179)
Net cash used in financing activities	(2,302)	(9,585)
Effect of exchange rate changes on cash and cash equivalents	(1,125)	(501)
Net decrease in cash and cash equivalents	(10,899)	(3,858)
Cash and cash equivalents - beginning of period	84,939	72,289
Cash and cash equivalents - end of period	74,040	68,431
Supplementary information:
Income taxes, net of refunds received	578	857
Interest payments	627	1,266
Goodwill	26,623
Cash paid for acquisitions, net of cash acquired	14,759	0
RMS and EOS Acquisitions [Member]
Supplementary information:
Fair value of identifiable net assets acquired	17,312	0
Goodwill	3,402	0
Fair value of net assets acquired	20,714	0
Fair value of consideration transferred	20,714	0
Less: Cash acquired in acquisitions	(4,677)	$ 0
Less: Deferred consideration	$ (1,278)

Note 1 - Basis of Presentation

Note 1 - Basis of Presentation and Accounting Policies	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Basis of Presentation and Significant Accounting Policies [Text Block]	1. BASIS OF PRESENTATION AND ACCOUNTING POLICIES The condensed consolidated balance sheets and statements of operations, comprehensive income (loss), stockholders’ equity and cash flows for the periods presented herein have been prepared by the Company and are unaudited. In the opinion of management, all adjustments (consisting solely of normal recurring adjustments) necessary to present fairly the consolidated financial position, results of operations and cash flows for all periods presented have been made. The results for the three March 31, 2021 not 10 December 31, 2020 Certain information and footnote disclosures required under accounting principles generally accepted in the United States of America (“U.S. GAAP”) have been condensed or omitted from these condensed consolidated financial statements pursuant to the rules and regulations, including the interim reporting requirements, of the U.S. Securities and Exchange Commission (“SEC”). The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts and the disclosure of contingent amounts in our condensed consolidated financial statements and accompanying notes. Actual results could differ from these estimates. The Company’s significant accounting policies are summarized in Note 1 10 December 31, 2020 no three March 31, 2021 Reclassifications fourth 2020, three March 31, 2020. All amounts included in the tables to these notes to condensed consolidated financial statements, except per share amounts, are in thousands. Recently Adopted Accounting Standards In August 2018, 2018 14, Compensation-Retirement Benefits-Defined Benefit Plans-General (Subtopic 715 20 Changes to the Disclosure Requirements for Defined Benefit Plans 2018 14" not 2018 14 January 1, 2021. not In December 2019, 2019 12, Simplifying the Accounting for Income Taxes 2019 12" 740 January 1, 2021 not Accounting Standards Issued But Not In June 2016, No. 2016 13, Financial Instruments Credit Losses (Topic 326 2016 13” , December 15, 2022, 2016 13, not In March 2020, No. 2020 04, Reference Rate Reform (Topic 848 2020 04" 2020 04 January 2021, 2021 01, 848 December 31, 2022.

Note 2 - Acquisitions

Note 2 - Acquisitions	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Business Combination Disclosure [Text Block]	2. ACQUISITIONS rms Connectors On January 8, 2021, 30 EOS Power On March 31, 2021, December 31, 2020. March 2021, April 2021 March 31, 2021. The acquisitions of rms Connectors and EOS may "2021 "2021 three March 31, 2021 2021 March 31, 2021. three March 31, 2021, 2021 While the initial accounting related to the 2021 not 10 Acquisition Date Fair Values rms EOS Total Cash and cash equivalents $ - $ 4,677 $ 4,677 Accounts receivable 1,283 1,805 3,088 Inventories 3,946 1,967 5,913 Other current assets 9 1,618 1,627 Property, plant and equipment 4,035 726 4,761 Other assets - 76 76 Total identifiable assets 9,273 10,869 20,142 Accounts payable (62 ) (2,148 ) (2,210 ) Accrued expenses (209 ) (411 ) (620 ) Total liabilities assumed (271 ) (2,559 ) (2,830 ) Net identifiable assets acquired 9,002 8,310 17,312 Goodwill - 3,402 3,402 Net assets acquired $ 9,002 $ 11,712 $ 20,714 Cash paid 9,130 10,434 19,564 Deferred consideration due (from) to seller (128 ) 1,278 1,150 Fair value of consideration transferred $ 9,002 $ 11,712 $ 20,714 The Company has identified intangible assets, including but not no one Based upon the preliminary purchase price allocation above, there is currently no goodwill associated with the rms acquisition. Any goodwill recognized in connection with the EOS acquisition would be allocated to the Company's Power Solutions and Protection segment and would not The results of operations of the 2021 three March 31, 2021, March 31, 2021, not three March 31, 2021. 2021 not may 2021 no not 2021 January 1, 2020, may The following unaudited pro forma consolidated results of operations assume that the acquisition of the 2021 January 1, 2020: Three Months Ended Three Months Ended March 31, 2021 March 31, 2020 Revenue $ 113,665 $ 108,054 Net earnings (loss) 3,429 (3,920 ) Earnings (loss) per Class A common share - basic and diluted 0.26 (0.31 ) Earnings (loss) per Class B common share - basic and diluted 0.28 (0.32 )

Note 3 - Revenue

Note 3 - Revenue	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Revenue from Contract with Customer [Text Block]	3. REVENUE The following table provides information about disaggregated revenue by geographic region and sales channel, and includes a reconciliation of the disaggregated revenue to our reportable segments: Three Months Ended March 31, 2021 Cinch Connectivity Solutions Power Solutions and Protection Magnetic Solutions Consolidated By Geographic Region: North America $ 29,542 $ 29,777 $ 7,077 $ 66,396 Europe 6,747 9,959 1,248 17,954 Asia 1,767 3,905 20,621 26,293 $ 38,056 $ 43,641 $ 28,946 $ 110,643 By Sales Channel: Direct to customer $ 23,637 $ 26,489 $ 24,335 $ 74,461 Through distribution 14,419 17,152 4,611 36,182 $ 38,056 $ 43,641 $ 28,946 $ 110,643 Three Months Ended March 31, 2020 Cinch Connectivity Solutions Power Solutions and Protection Magnetic Solutions Consolidated By Geographic Region: North America $ 29,703 $ 22,723 $ 7,107 $ 59,533 Europe 7,762 9,314 1,201 18,277 Asia 1,635 4,140 20,393 26,168 $ 39,100 $ 36,177 $ 28,701 $ 103,978 By Sales Channel: Direct to customer $ 25,053 $ 21,577 $ 24,342 $ 70,972 Through distribution 14,047 14,600 4,359 33,006 $ 39,100 $ 36,177 $ 28,701 $ 103,978 March 31, 2021 December 31, 2020 March 31, December 31, 2021 2020 Contract assets - current (unbilled receivables) $ 12,868 $ 14,135 Contract liabilities - current (deferred revenue) $ 2,294 $ 2,077 The change in balance of our unbilled receivables from December 31, 2020 March 31, 2021 The aggregate amount of transaction price allocated to remaining performance obligations that have not March 31, 2021 one 2022 2025. 2022, 2023 2023.

Note 4 - Earnings (Loss) Per Sh

Note 4 - Earnings (Loss) Per Share	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Earnings Per Share [Text Block]	4. EARNINGS (LOSS) PER SHARE The following table sets forth the calculation of basic and diluted net earnings (loss) per common share under the two three March 31, 2021 2020 Three Months Ended March 31, 2021 2020 Numerator: Net earnings (loss) $ 3,199 $ (3,804 ) Less dividends declared: Class A 128 130 Class B 716 709 Undistributed earnings (loss) $ 2,355 $ (4,643 ) Undistributed earnings (loss) allocation - basic and diluted: Class A undistributed earnings (loss) $ 394 $ (780 ) Class B undistributed earnings (loss) 1,961 (3,863 ) Total undistributed earnings (loss) $ 2,355 $ (4,643 ) Net earnings (loss) allocation - basic and diluted: Class A net earnings (loss) $ 522 $ (649 ) Class B net earnings (loss) 2,677 (3,155 ) Net earnings (loss) $ 3,199 $ (3,804 ) Denominator: Weighted-average shares outstanding: Class A - basic and diluted 2,145 2,145 Class B - basic and diluted 10,203 10,123 Net earnings (loss) per share: Class A - basic and diluted $ 0.24 $ (0.30 ) Class B - basic and diluted $ 0.26 $ (0.31 )

Note 5 - Fair Value Measurement

Note 5 - Fair Value Measurements	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Fair Value Disclosures [Text Block]	5. FAIR VALUE MEASUREMENTS Fair value is defined as an exit price, representing the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants based upon the best use of the asset or liability at the measurement date. Entities are required to use a fair value hierarchy which maximizes the use of observable inputs and minimizes the use of unobservable inputs when measuring fair value. There are three may Level 1 Level 2 Level 3 no As of March 31, 2021 December 31, 2020 1 March 31, 2021 December 31, 2020 first 2021, March 31, 2021. not 3, no 3 three March 31, 2021 March 31, 2020 no three March 31, 2021 March 31, 2020 There were no March 31, 2021 December 31, 2020 The Company has other financial instruments, such as cash and cash equivalents, accounts receivable, restricted cash, accounts payable and accrued expenses, which are not March 31, 2021 December 31, 2020 not March 31, 2021 Nonfinancial assets and liabilities, such as goodwill, indefinite-lived intangible assets and long-lived assets, are accounted for at fair value on a nonrecurring basis. These items are tested for impairment upon the occurrence of a triggering event or in the case of goodwill, on at least an annual basis. The Company considered the impacts of COVID- 19 three March 31, 2021. no three March 31, 2021

Note 6 - Inventories

Note 6 - Inventories	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Inventory Disclosure [Text Block]	6. INVENTORIES The components of inventories are as follows: March 31, December 31, 2021 2020 Raw materials $ 43,208 $ 40,846 Work in progress 29,866 25,916 Finished goods 33,663 33,371 Inventories $ 106,737 $ 100,133

Note 7 - Property, Plant and Eq

Note 7 - Property, Plant and Equipment, Net	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Property, Plant and Equipment Disclosure [Text Block]	7. PROPERTY, PLANT AND EQUIPMENT Property, plant and equipment consist of the following: March 31, December 31, 2021 2020 Land $ 1,107 $ 1,115 Buildings and improvements 20,744 19,917 Machinery and equipment 127,061 124,114 Construction in progress 2,071 1,603 150,983 146,749 Accumulated depreciation (113,118 ) (112,248 ) Property, plant and equipment, net $ 37,865 $ 34,501 Depreciation expense for the three March 31, 2021 2020 At March 31, 2021,

Note 8 - Accrued Expenses

Note 8 - Accrued Expenses	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Accounts Payable and Accrued Liabilities Disclosure [Text Block]	8. ACCRUED EXPENSES Accrued expenses consist of the following: March 31, December 31, 2021 2020 Sales commissions $ 2,528 $ 2,574 Subcontracting labor 1,622 758 Salaries, bonuses and related benefits 15,444 17,165 Warranty accrual 1,315 1,010 Other 8,267 6,969 $ 29,176 $ 28,476 The change in warranty accrual during the three March 31, 2021 no three March 31, 2021 Restructuring Activities Included within other accrued expenses in the table above are costs accrued related to the Company’s restructuring activities. Activity and liability balances related to restructuring costs for the three March 31, 2021 Three Months Ended March 31, 2021 Liability at Cash Payments Liability at December 31, New and Other March 31, 2020 Charges Settlements 2021 Severance costs $ 124 $ - $ (124 ) $ - Other restructuring costs - - - - Total $ 124 $ - $ (124 ) $ -

Note 9 - Debt

Note 9 - Debt	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Debt Disclosure [Text Block]	9. DEBT The Company has a Credit and Security Agreement with KeyBank National Association (as amended, the "credit agreement" or the "CSA"). The CSA consists of (i) a term loan, with outstanding borrowings of $103.3 million and $104.8 million at March 31, 2021 December 31, 2020 March 31, 2021 December 31, 2020 December 11, 2022. March 31, 2021 December 31, 2020 On February 3, 2021, The weighted-average interest rate in effect was 2.13% at March 31, 2021 December 31, 2020 three March 31, 2021 March 31, 2020 The CSA contains customary representations and warranties, covenants and events of default and financial covenants that measure (i) the ratio of the Company's total funded indebtedness, on a consolidated basis, to the amount of the Company’s consolidated EBITDA, as defined (“Leverage Ratio”) and (ii) the ratio of the amount of the Company’s consolidated EBITDA to the Company’s consolidated fixed charges ("Fixed Charge Coverage Ratio"). If an event of default occurs, the lenders under the CSA would be entitled to take various actions, including the acceleration of amounts due thereunder and all actions permitted to be taken by a secured creditor. At March 31, 2021

Note 10 - Income Taxes

Note 10 - Income Taxes	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Income Tax Disclosure [Text Block]	10. INCOME TAXES The Company's estimated taxable income in future periods is not not no 2017 2014. no 2010 2012 As a result of the expiration of the statutes of limitations for specific jurisdictions, it is reasonably possible that the related unrecognized benefits for tax positions taken regarding previously filed tax returns may March 31, 2021. March 31, 2021 December 31, 2020, December 31, 2020 2021 The Company’s policy is to recognize interest and penalties related to uncertain tax positions as a component of the current provision for income taxes. During the three March 31, 2021 2020, March 31, 2021 December 31, 2020,

Note 11 - Retirement Fund and P

Note 11 - Retirement Fund and Profit Sharing Plan	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Retirement Benefits [Text Block]	11. RETIREMENT FUND AND PROFIT SHARING PLAN The Company maintains the Bel Fuse Inc. Employees’ Savings Plan, a defined contribution plan that is intended to meet the applicable requirements for tax-qualification under sections 401 1986, three March 31, 2021 2020 March 31, 2021 The Company's subsidiaries in Asia have a retirement fund covering substantially all of their Hong Kong based full-time employees. The expense for the three March 31, 2021 2020 March 31, 2021 The Company maintains a SERP, which is designed to provide a limited group of key management and other key employees of the Company with supplemental retirement and death benefits. As discussed in Note 5 The components of SERP expense are as follows: Three Months Ended March 31, 2021 2020 Service cost $ 169 $ 150 Interest cost 135 159 Net amortization 127 86 Net periodic benefit cost $ 431 $ 395 The service cost component of net benefit cost is presented within cost of sales or selling, general and administrative expense on the accompanying condensed consolidated statements of operations, in accordance with where compensation cost for the related associate is reported. All other components of net benefit cost, including interest cost and net amortization noted above, are presented within other income (expense), net in the accompanying condensed consolidated statements of operations. The following amounts are recognized net of tax in accumulated other comprehensive loss: March 31, December 31, 2021 2020 Prior service cost $ 555 $ 586 Net loss 1,678 1,773 $ 2,233 $ 2,359

Note 12 - Accumulated Other Com

Note 12 - Accumulated Other Comprehensive Loss	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Comprehensive Income (Loss) Note [Text Block]	12. ACCUMULATED OTHER COMPREHENSIVE LOSS The components of accumulated other comprehensive loss at March 31, 2021 December 31, 2020 March 31, December 31, 2021 2020 Foreign currency translation adjustment, net of taxes of ($759) ($750) $ (15,671 ) $ (13,142 ) Unrealized holding gains on available-for-sale securities, net of taxes of $0 $0 18 19 Unfunded SERP liability, net of taxes of ($1,349) ($1,377) (4,841 ) (4,940 ) Accumulated other comprehensive loss $ (20,494 ) $ (18,063 ) Changes in accumulated other comprehensive loss by component during the three March 31, 2021 Unrealized Holding Foreign Currency Gains on Translation Available-for- Unfunded Adjustment Sale Securities SERP Liability Total Balance at December 31, 2020 $ (13,142 ) $ 19 $ (4,940 ) $ (18,063 ) Other comprehensive income (loss) before reclassifications (2,529 ) (1 ) 2 (2,528 ) Amount reclassified from accumulated other comprehensive income (loss) - - 97 (a) 97 Net current period other comprehensive (loss) income (2,529 ) (1 ) 99 (2,431 ) Balance at March 31, 2021 $ (15,671 ) $ 18 $ (4,841 ) $ (20,494 ) (a) This reclassification relates to the amortization of prior service costs and gains/losses associated with the Company's SERP Plan. This expense is reflected in other income (expense), net on the accompanying condensed consolidated statement of operations.

Note 13 - Commitments and Conti

Note 13 - Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Commitments and Contingencies Disclosure [Text Block]	13. COMMITMENTS AND CONTINGENCIES Legal Proceedings In connection with the Company's 2014 2004 2006. September 2012, February 2013, October 2, 2014. October 13, 2014, July 18, 2015 December 5, 2016, January 4, 2017. March 31, 2021 December 31, 2020 The Company is not

Note 14 - Segments

Note 14 - Segments	3 Months Ended
	Mar. 31, 2021
Notes to Financial Statements
Segment Reporting Disclosure [Text Block]	14. SEGMENTS The Company operates in one three three Three Months Ended March 31, 2021 Cinch Connectivity Power Solutions Magnetic Corporate Solutions and Protection Solutions Segment Total Revenue $ 38,056 $ 43,641 $ 28,946 $ - $ 110,643 Gross Profit 9,773 10,782 3,961 (257 ) 24,259 Gross Profit % 25.7 % 24.7 % 13.7 % nm 21.9 % Three Months Ended March 31, 2020 Cinch Connectivity Power Solutions Magnetic Corporate Solutions and Protection Solutions Segment Total Revenue $ 39,100 $ 36,177 $ 28,701 $ - $ 103,978 Gross Profit 11,194 8,798 6,076 (310 ) 25,758 Gross Profit % 28.6 % 24.3 % 21.2 % nm 24.8 %

Significant Accounting Policies

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Reclassification, Comparability Adjustment [Policy Text Block]	Reclassifications fourth 2020, three March 31, 2020. All amounts included in the tables to these notes to condensed consolidated financial statements, except per share amounts, are in thousands.
New Accounting Pronouncements, Policy [Policy Text Block]	Recently Adopted Accounting Standards In August 2018, 2018 14, Compensation-Retirement Benefits-Defined Benefit Plans-General (Subtopic 715 20 Changes to the Disclosure Requirements for Defined Benefit Plans 2018 14" not 2018 14 January 1, 2021. not In December 2019, 2019 12, Simplifying the Accounting for Income Taxes 2019 12" 740 January 1, 2021 not Accounting Standards Issued But Not In June 2016, No. 2016 13, Financial Instruments Credit Losses (Topic 326 2016 13” , December 15, 2022, 2016 13, not In March 2020, No. 2020 04, Reference Rate Reform (Topic 848 2020 04" 2020 04 January 2021, 2021 01, 848 December 31, 2022.

Note 2 - Acquisitions (Tables)

Note 2 - Acquisitions (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]	Acquisition Date Fair Values rms EOS Total Cash and cash equivalents $ - $ 4,677 $ 4,677 Accounts receivable 1,283 1,805 3,088 Inventories 3,946 1,967 5,913 Other current assets 9 1,618 1,627 Property, plant and equipment 4,035 726 4,761 Other assets - 76 76 Total identifiable assets 9,273 10,869 20,142 Accounts payable (62 ) (2,148 ) (2,210 ) Accrued expenses (209 ) (411 ) (620 ) Total liabilities assumed (271 ) (2,559 ) (2,830 ) Net identifiable assets acquired 9,002 8,310 17,312 Goodwill - 3,402 3,402 Net assets acquired $ 9,002 $ 11,712 $ 20,714 Cash paid 9,130 10,434 19,564 Deferred consideration due (from) to seller (128 ) 1,278 1,150 Fair value of consideration transferred $ 9,002 $ 11,712 $ 20,714
Business Acquisition, Pro Forma Information [Table Text Block]	Three Months Ended Three Months Ended March 31, 2021 March 31, 2020 Revenue $ 113,665 $ 108,054 Net earnings (loss) 3,429 (3,920 ) Earnings (loss) per Class A common share - basic and diluted 0.26 (0.31 ) Earnings (loss) per Class B common share - basic and diluted 0.28 (0.32 )

Note 3 - Revenue (Tables)

Note 3 - Revenue (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Disaggregation of Revenue [Table Text Block]	Three Months Ended March 31, 2021 Cinch Connectivity Solutions Power Solutions and Protection Magnetic Solutions Consolidated By Geographic Region: North America $ 29,542 $ 29,777 $ 7,077 $ 66,396 Europe 6,747 9,959 1,248 17,954 Asia 1,767 3,905 20,621 26,293 $ 38,056 $ 43,641 $ 28,946 $ 110,643 By Sales Channel: Direct to customer $ 23,637 $ 26,489 $ 24,335 $ 74,461 Through distribution 14,419 17,152 4,611 36,182 $ 38,056 $ 43,641 $ 28,946 $ 110,643 Three Months Ended March 31, 2020 Cinch Connectivity Solutions Power Solutions and Protection Magnetic Solutions Consolidated By Geographic Region: North America $ 29,703 $ 22,723 $ 7,107 $ 59,533 Europe 7,762 9,314 1,201 18,277 Asia 1,635 4,140 20,393 26,168 $ 39,100 $ 36,177 $ 28,701 $ 103,978 By Sales Channel: Direct to customer $ 25,053 $ 21,577 $ 24,342 $ 70,972 Through distribution 14,047 14,600 4,359 33,006 $ 39,100 $ 36,177 $ 28,701 $ 103,978
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block]	March 31, December 31, 2021 2020 Contract assets - current (unbilled receivables) $ 12,868 $ 14,135 Contract liabilities - current (deferred revenue) $ 2,294 $ 2,077

Note 4 - Earnings (Loss) Per _2

Note 4 - Earnings (Loss) Per Share (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	Three Months Ended March 31, 2021 2020 Numerator: Net earnings (loss) $ 3,199 $ (3,804 ) Less dividends declared: Class A 128 130 Class B 716 709 Undistributed earnings (loss) $ 2,355 $ (4,643 ) Undistributed earnings (loss) allocation - basic and diluted: Class A undistributed earnings (loss) $ 394 $ (780 ) Class B undistributed earnings (loss) 1,961 (3,863 ) Total undistributed earnings (loss) $ 2,355 $ (4,643 ) Net earnings (loss) allocation - basic and diluted: Class A net earnings (loss) $ 522 $ (649 ) Class B net earnings (loss) 2,677 (3,155 ) Net earnings (loss) $ 3,199 $ (3,804 ) Denominator: Weighted-average shares outstanding: Class A - basic and diluted 2,145 2,145 Class B - basic and diluted 10,203 10,123 Net earnings (loss) per share: Class A - basic and diluted $ 0.24 $ (0.30 ) Class B - basic and diluted $ 0.26 $ (0.31 )

Note 6 - Inventories (Tables)

Note 6 - Inventories (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Schedule of Inventory, Current [Table Text Block]	March 31, December 31, 2021 2020 Raw materials $ 43,208 $ 40,846 Work in progress 29,866 25,916 Finished goods 33,663 33,371 Inventories $ 106,737 $ 100,133

Note 7 - Property, Plant and _2

Note 7 - Property, Plant and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Property, Plant and Equipment [Table Text Block]	March 31, December 31, 2021 2020 Land $ 1,107 $ 1,115 Buildings and improvements 20,744 19,917 Machinery and equipment 127,061 124,114 Construction in progress 2,071 1,603 150,983 146,749 Accumulated depreciation (113,118 ) (112,248 ) Property, plant and equipment, net $ 37,865 $ 34,501

Note 8 - Accrued Expenses (Tabl

Note 8 - Accrued Expenses (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Schedule of Accrued Liabilities [Table Text Block]	March 31, December 31, 2021 2020 Sales commissions $ 2,528 $ 2,574 Subcontracting labor 1,622 758 Salaries, bonuses and related benefits 15,444 17,165 Warranty accrual 1,315 1,010 Other 8,267 6,969 $ 29,176 $ 28,476
Restructuring and Related Costs [Table Text Block]	Three Months Ended March 31, 2021 Liability at Cash Payments Liability at December 31, New and Other March 31, 2020 Charges Settlements 2021 Severance costs $ 124 $ - $ (124 ) $ - Other restructuring costs - - - - Total $ 124 $ - $ (124 ) $ -

Note 11 - Retirement Fund and_2

Note 11 - Retirement Fund and Profit Sharing Plan (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Schedule of Net Benefit Costs [Table Text Block]	Three Months Ended March 31, 2021 2020 Service cost $ 169 $ 150 Interest cost 135 159 Net amortization 127 86 Net periodic benefit cost $ 431 $ 395
Schedule of Amounts Recognized in Other Comprehensive Income (Loss) [Table Text Block]	March 31, December 31, 2021 2020 Prior service cost $ 555 $ 586 Net loss 1,678 1,773 $ 2,233 $ 2,359

Note 12 - Accumulated Other C_2

Note 12 - Accumulated Other Comprehensive Loss (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	March 31, December 31, 2021 2020 Foreign currency translation adjustment, net of taxes of ($759) ($750) $ (15,671 ) $ (13,142 ) Unrealized holding gains on available-for-sale securities, net of taxes of $0 $0 18 19 Unfunded SERP liability, net of taxes of ($1,349) ($1,377) (4,841 ) (4,940 ) Accumulated other comprehensive loss $ (20,494 ) $ (18,063 )
Schedule of Changes in Accumulated Other Comprehensive Income (Loss) by Component [Table Text Block]	Unrealized Holding Foreign Currency Gains on Translation Available-for- Unfunded Adjustment Sale Securities SERP Liability Total Balance at December 31, 2020 $ (13,142 ) $ 19 $ (4,940 ) $ (18,063 ) Other comprehensive income (loss) before reclassifications (2,529 ) (1 ) 2 (2,528 ) Amount reclassified from accumulated other comprehensive income (loss) - - 97 (a) 97 Net current period other comprehensive (loss) income (2,529 ) (1 ) 99 (2,431 ) Balance at March 31, 2021 $ (15,671 ) $ 18 $ (4,841 ) $ (20,494 )

Note 14 - Segments (Tables)

Note 14 - Segments (Tables)	3 Months Ended
	Mar. 31, 2021
Notes Tables
Schedule of Segment Reporting Information, by Segment [Table Text Block]	Three Months Ended March 31, 2021 Cinch Connectivity Power Solutions Magnetic Corporate Solutions and Protection Solutions Segment Total Revenue $ 38,056 $ 43,641 $ 28,946 $ - $ 110,643 Gross Profit 9,773 10,782 3,961 (257 ) 24,259 Gross Profit % 25.7 % 24.7 % 13.7 % nm 21.9 % Three Months Ended March 31, 2020 Cinch Connectivity Power Solutions Magnetic Corporate Solutions and Protection Solutions Segment Total Revenue $ 39,100 $ 36,177 $ 28,701 $ - $ 103,978 Gross Profit 11,194 8,798 6,076 (310 ) 25,758 Gross Profit % 28.6 % 24.3 % 21.2 % nm 24.8 %

Note 1 - Basis of Presentatio_2

Note 1 - Basis of Presentation and Accounting Policies (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cost of Goods and Services Sold, Total	$ 86,384	$ 78,220
Nonoperating Income (Expense), Total	546	(2,106)
Selling, General and Administrative Expense, Total	20,995	20,690
Revision of Prior Period, Adjustment [Member] | Cost of Sales Reclassified to Other (Expense) Income, Net [Member]
Cost of Goods and Services Sold, Total		(600)
Nonoperating Income (Expense), Total		(600)
Revision of Prior Period, Adjustment [Member] | Selling, General and Administrative Expenses Reclassified to Other (Expense) Income, Net [Member]
Nonoperating Income (Expense), Total		(1,400)
Selling, General and Administrative Expense, Total		(1,400)
Supplemental Employee Retirement Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Total	$ 431	395
Supplemental Employee Retirement Plan [Member] | Revision of Prior Period, Adjustment [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Total		$ 2,000

Note 2 - Acquisitions (Details

Note 2 - Acquisitions (Details Textual) - USD ($) $ in Thousands	Mar. 31, 2021	Jan. 08, 2021	Apr. 30, 2021	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Payments to Acquire Businesses, Net of Cash Acquired, Total				$ 14,759	$ 0
Goodwill, Ending Balance	$ 26,623			26,623		$ 23,966
EOS Power Panama Inc. [Member]
Revenues, Total						$ 12,000
EOS Power Panama Inc. [Member] | Subsequent Event [Member]
Payments to Acquire Businesses, Gross			$ 1,300
rms Connectors, Inc. [Member]
Payments to Acquire Businesses, Net of Cash Acquired, Total		$ 8,500
Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Consideration Transferred		(100)
Payments to Acquire Businesses, Gross		9,130
Goodwill, Ending Balance		$ 0
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual				2,100
Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual				400
EOS Power Panama Inc. [Member]
Business Combination, Consideration Transferred, Equity Interests Issued and Issuable	7,000
Payments to Acquire Businesses, Gross	10,434
Goodwill, Ending Balance	3,402			3,402
The 2021 Acquisitions [Member]
Payments to Acquire Businesses, Gross				19,564
Business Combination, Acquisition Related Costs				200
Goodwill, Ending Balance	$ 3,402			$ 3,402

Note 2 - Acquisitions - Identif

Note 2 - Acquisitions - Identifiable Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Jan. 08, 2021	Mar. 31, 2021	Dec. 31, 2020
Goodwill, Ending Balance	$ 26,623		$ 26,623	$ 23,966
rms Connectors, Inc. [Member]
Cash and cash equivalents		$ 0
Accounts receivable		1,283
Inventories		3,946
Other current assets		9
Property, plant and equipment		4,035
Other assets		0
Total identifiable assets		9,273
Accounts payable		(62)
Accrued expenses		(209)
Total liabilities assumed		(271)
Net identifiable assets acquired		9,002
Goodwill, Ending Balance		0
Net assets acquired		9,002
Payments to Acquire Businesses, Gross		9,130
Deferred consideration due (from) to seller		(128)
Fair value of consideration transferred		$ 9,002
EOS Power Panama Inc. [Member]
Cash and cash equivalents	4,677		4,677
Accounts receivable	1,805		1,805
Inventories	1,967		1,967
Other current assets	1,618		1,618
Property, plant and equipment	726		726
Other assets	76		76
Total identifiable assets	10,869		10,869
Accounts payable	(2,148)		(2,148)
Accrued expenses	(411)		(411)
Total liabilities assumed	(2,559)		(2,559)
Net identifiable assets acquired	8,310		8,310
Goodwill, Ending Balance	3,402		3,402
Net assets acquired	11,712		11,712
Payments to Acquire Businesses, Gross	10,434
Deferred consideration due (from) to seller	1,278
Fair value of consideration transferred	11,712
The 2021 Acquisitions [Member]
Cash and cash equivalents	4,677		4,677
Accounts receivable	3,088		3,088
Inventories	5,913		5,913
Other current assets	1,627		1,627
Property, plant and equipment	4,761		4,761
Other assets	76		76
Total identifiable assets	20,142		20,142
Accounts payable	(2,210)		(2,210)
Accrued expenses	(620)		(620)
Total liabilities assumed	(2,830)		(2,830)
Net identifiable assets acquired	17,312		17,312
Goodwill, Ending Balance	3,402		3,402
Net assets acquired	$ 20,714		20,714
Payments to Acquire Businesses, Gross			19,564
Deferred consideration due (from) to seller			1,150
Fair value of consideration transferred			$ 20,714

Note 2 - Acquisitions - Proform

Note 2 - Acquisitions - Proforma Results (Details) - The 2021 Acquisitions [Member] - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue	$ 113,665	$ 108,054
Net earnings (loss)	$ 3,429	$ (3,920)
Common Class A [Member]
Earnings (loss) per Class A common share - basic and diluted (in dollars per share)	$ 0.26	$ (0.31)
Common Class B [Member]
Earnings (loss) per Class A common share - basic and diluted (in dollars per share)	$ 0.28	$ (0.32)

Note 3 - Revenue 1 (Details Tex

Note 3 - Revenue 1 (Details Textual) $ in Millions	Mar. 31, 2021USD ($)
Revenue, Remaining Performance Obligation, Amount	$ 11.5

Note 3 - Revenue 2 (Details Tex

Note 3 - Revenue 2 (Details Textual)	Mar. 31, 2021
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period (Year)	1 year
Revenue, Remaining Performance Obligation, Percentage	70.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period (Year)	1 year
Revenue, Remaining Performance Obligation, Percentage	8.00%

Note 3 - Revenue - Disaggregati

Note 3 - Revenue - Disaggregation of Revenue by Product Group and Sales Channel (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue	$ 110,643	$ 103,978
Sales Channel, Directly to Consumer [Member]
Revenue	74,461	70,972
Sales Channel, Through Intermediary [Member]
Revenue	36,182	33,006
Connectivity Solutions [Member]
Revenue	38,056	39,100
Connectivity Solutions [Member] | Sales Channel, Directly to Consumer [Member]
Revenue	23,637	25,053
Connectivity Solutions [Member] | Sales Channel, Through Intermediary [Member]
Revenue	14,419	14,047
Power Solutions and Protection [Member]
Revenue	43,641	36,177
Power Solutions and Protection [Member] | Sales Channel, Directly to Consumer [Member]
Revenue	26,489	21,577
Power Solutions and Protection [Member] | Sales Channel, Through Intermediary [Member]
Revenue	17,152	14,600
Magnetic Solutions [Member]
Revenue	28,946	28,701
Magnetic Solutions [Member] | Sales Channel, Directly to Consumer [Member]
Revenue	24,335	24,342
Magnetic Solutions [Member] | Sales Channel, Through Intermediary [Member]
Revenue	4,611	4,359
North America [Member]
Revenue	66,396	59,533
North America [Member] | Connectivity Solutions [Member]
Revenue	29,542	29,703
North America [Member] | Power Solutions and Protection [Member]
Revenue	29,777	22,723
North America [Member] | Magnetic Solutions [Member]
Revenue	7,077	7,107
Europe [Member]
Revenue	17,954	18,277
Europe [Member] | Connectivity Solutions [Member]
Revenue	6,747	7,762
Europe [Member] | Power Solutions and Protection [Member]
Revenue	9,959	9,314
Europe [Member] | Magnetic Solutions [Member]
Revenue	1,248	1,201
Asia [Member]
Revenue	26,293	26,168
Asia [Member] | Connectivity Solutions [Member]
Revenue	1,767	1,635
Asia [Member] | Power Solutions and Protection [Member]
Revenue	3,905	4,140
Asia [Member] | Magnetic Solutions [Member]
Revenue	$ 20,621	$ 20,393

Note 3 - Revenue - Contract Ass

Note 3 - Revenue - Contract Assets and Contract Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Contract assets - current (unbilled receivables)	$ 12,868	$ 14,135
Contract liabilities - current (deferred revenue)	$ 2,294	$ 2,077

Note 4 - Earnings (Loss) Per _3

Note 4 - Earnings (Loss) Per Share - Basic and Diluted Net Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Net earnings (loss)	$ 3,199	$ (3,804)
Undistributed earnings (loss)	2,355	(4,643)
Common Class A [Member]
Net earnings (loss)	522	(649)
Less dividends declared	128	130
Undistributed earnings (loss)	$ 394	$ (780)
Weighted-average shares outstanding, basic and diluted (in shares)	2,145	2,145
Common shares - basic and diluted (in dollars per share)	$ 0.24	$ (0.30)
Common Class B [Member]
Net earnings (loss)	$ 2,677	$ (3,155)
Less dividends declared	716	709
Undistributed earnings (loss)	$ 1,961	$ (3,863)
Weighted-average shares outstanding, basic and diluted (in shares)	10,203	10,123
Common shares - basic and diluted (in dollars per share)	$ 0.26	$ (0.31)

Note 5 - Fair Value Measureme_2

Note 5 - Fair Value Measurements (Details Textual) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Long-term Debt, Fair Value	$ 116,200	$ 118,400
Long-term Debt, Gross	114,300	115,600
Fair Value, Nonrecurring [Member]
Assets, Fair Value Disclosure	0	0
Foreign Exchange Forward [Member] | Maximum [Member]
Derivative Asset, Total	100
Investments Held in Rabbi Trust [Member]
Debt Securities, Available-for-sale, Total	$ 600	$ 700

Note 6 - Inventories - Componen

Note 6 - Inventories - Components of Inventories (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Raw materials	$ 43,208	$ 40,846
Work in progress	29,866	25,916
Finished goods	33,663	33,371
Inventories	$ 106,737	$ 100,133

Note 7 - Property, Plant and _3

Note 7 - Property, Plant and Equipment, Net (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Depreciation, Total	$ 2,400	$ 2,300
Assets Held-for-sale, Not Part of Disposal Group, Current, Total	$ 1,635		$ 0

Note 7 - Property, Plant and _4

Note 7 - Property, Plant and Equipment, Net - Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Property, plant and equipment, gross	$ 150,983	$ 146,749
Accumulated depreciation	(113,118)	(112,248)
Property, plant and equipment, net	37,865	34,501
Land [Member]
Property, plant and equipment, gross	1,107	1,115
Building and Building Improvements [Member]
Property, plant and equipment, gross	20,744	19,917
Machinery and Equipment [Member]
Property, plant and equipment, gross	127,061	124,114
Construction in Progress [Member]
Property, plant and equipment, gross	$ 2,071	$ 1,603

Note 8 - Accrued Expenses - Acc

Note 8 - Accrued Expenses - Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Sales commissions	$ 2,528	$ 2,574
Subcontracting labor	1,622	758
Salaries, bonuses and related benefits	15,444	17,165
Warranty accrual	1,315	1,010
Other	8,267	6,969
Accrued Liabilities, Current, Total	$ 29,176	$ 28,476

Note 8 - Accrued Expenses - Act

Note 8 - Accrued Expenses - Activity and Liability Balances Related to Restructuring Costs (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Liability, beginning balance	$ 124
New charges	0
Cash payment and other settlements	(124)
Liability, ending balance	0
Employee Severance [Member]
Liability, beginning balance	124
New charges	0
Cash payment and other settlements	(124)
Liability, ending balance	0
Other Restructuring [Member]
Liability, beginning balance	0
New charges	0
Cash payment and other settlements	0
Liability, ending balance	$ 0

Note 9 - Debt (Details Textual)

Note 9 - Debt (Details Textual) - Credit and Security Agreement with KeyBank [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Debt Issuance Costs, Net, Total	$ 1.1		$ 1.3
Line of Credit Facility, Interest Rate at Period End	2.13%		2.19%
Interest Expense, Debt, Total	$ 0.8	$ 1.4
Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity	75
Long-term Line of Credit, Total	12
Term Loan [Member]
Long-term Debt, Total	$ 103.3		$ 104.8

Note 10 - Income Taxes (Details

Note 10 - Income Taxes (Details Textual) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Unrecognized Tax Benefits, Ending Balance	$ 28.7		$ 28.5
Liability for Uncertainty in Income Taxes, Current			2.4
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount	0.2	$ 0.2
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued, Total	$ 5.4		$ 5.2
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Open Tax Year	2017 2018 2019 2020
State and Local Jurisdiction [Member]
Open Tax Year	2014 2015 2016 2017 2018 2019 2020
Foreign Tax Authority [Member] | Asia [Member]
Open Tax Year	2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Foreign Tax Authority [Member] | Europe [Member]
Open Tax Year	2012 2013 2014 2015 2016 2017 2018 2019 2020

Note 11 - Retirement Fund and_3

Note 11 - Retirement Fund and Profit Sharing Plan (Details Textual) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Bel Fuse Inc. Employees' Savings Plan [Member]
Defined Contribution Plan, Cost	$ 0.3	$ 0.3
Bel Fuse Inc. Employees' Savings Plan [Member] | Common Class A [Member]
Shares Held in Plan (in shares)	268,020
Bel Fuse Inc. Employees' Savings Plan [Member] | Common Class B [Member]
Shares Held in Plan (in shares)	108,919
Retirement Fund Covering Hong Kong-based Employees [Member]
Defined Contribution Plan, Cost	$ 0.1	$ 0.1
Retirement Fund Covering Hong Kong-based Employees [Member] | Common Class A [Member]
Shares Held in Plan (in shares)	3,323
Retirement Fund Covering Hong Kong-based Employees [Member] | Common Class B [Member]
Shares Held in Plan (in shares)	17,342

Note 11 - Retirement Fund and_4

Note 11 - Retirement Fund and Profit Sharing Plan - Components of SERP Expense (Details) - Supplemental Employee Retirement Plan [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Service cost	$ 169	$ 150
Interest cost	135	159
Net amortization	127	86
Net periodic benefit cost	$ 431	$ 395

Note 11 - Retirement Fund and_5

Note 11 - Retirement Fund and Profit Sharing Plan - Amounts Recognized in Accumulated Other Comprehensive Loss (Details) - Supplemental Employee Retirement Plan [Member] - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Prior service cost	$ 555	$ 586
Net loss	1,678	1,773
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax, Total	$ 2,233	$ 2,359

Note 12 - Accumulated Other C_3

Note 12 - Accumulated Other Comprehensive Loss - Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Foreign currency translation adjustment, net of taxes of ($759) at March 31, 2021 and ($750) at December 31, 2020	$ (15,671)	$ (13,142)
Unrealized holding gains on available-for-sale securities, net of taxes of $0 at March 31, 2021 and $0 at December 31, 2020	18	19
Unfunded SERP liability, net of taxes of ($1,349) at March 31, 2021 and ($1,377) at December 31, 2020	(4,841)	(4,940)
Accumulated other comprehensive loss	$ (20,494)	$ (18,063)

Note 12 - Accumulated Other C_4

Note 12 - Accumulated Other Comprehensive Loss - Accumulated Other Comprehensive Loss (Details) (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Foreign currency translation adjustment, tax	$ (759)	$ (750)
Unrealized holding gains on available-for-sale securities, tax	0	0
Change in unfunded SERP liabilityChange in unfunded SERP liability, tax, tax	$ (1,349)	$ (1,377)

Note 12 - Accumulated Other C_5

Note 12 - Accumulated Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Loss by Component (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Balance		$ 185,799	$ 168,051
Other comprehensive loss		(2,431)	(2,179)
Balance		186,323	161,832
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Balance		(13,142)
Other comprehensive income (loss) before reclassifications		(2,529)
Amount reclassified from accumulated other comprehensive income (loss)		0
Other comprehensive loss		(2,529)
Balance		(15,671)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
Balance		19
Other comprehensive income (loss) before reclassifications		(1)
Amount reclassified from accumulated other comprehensive income (loss)		0
Other comprehensive loss		(1)
Balance		18
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balance		(4,940)
Other comprehensive income (loss) before reclassifications		2
Amount reclassified from accumulated other comprehensive income (loss)	[1]	97
Other comprehensive loss		99
Balance		(4,841)
AOCI Attributable to Parent [Member]
Balance		(18,063)	(24,065)
Other comprehensive income (loss) before reclassifications		(2,528)
Amount reclassified from accumulated other comprehensive income (loss)		97
Other comprehensive loss		(2,431)
Balance		$ (20,494)	$ (26,244)
[1]	This reclassification relates to the amortization of prior service costs and gains/losses associated with the Company's SERP Plan. This expense is reflected in other income (expense), net on the accompanying condensed consolidated statement of operations.

Note 13 - Commitments and Con_2

Note 13 - Commitments and Contingencies (Details Textual) $ in Millions	Mar. 31, 2021USD ($)
Arezzo Revenue Agency [Member]
Loss Contingency, Estimate of Possible Loss	$ 12

Note 14 - Segments (Details Tex

Note 14 - Segments (Details Textual)	3 Months Ended
	Mar. 31, 2021
Number of Industry in which Entity Operates	1
Number of Operating Segments	3
Number of Reportable Segments	3

Note 14 - Segments - Segments (

Note 14 - Segments - Segments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue	$ 110,643	$ 103,978
Gross Profit	$ 24,259	$ 25,758
Gross Profit %	21.90%	24.80%
Connectivity Solutions [Member]
Revenue	$ 38,056	$ 39,100
Gross Profit	$ 9,773	$ 11,194
Gross Profit %	25.70%	28.60%
Power Solutions and Protection Segment [Member]
Revenue	$ 43,641	$ 36,177
Gross Profit	$ 10,782	$ 8,798
Gross Profit %	24.70%	24.30%
Magnetic Solutions Segment [Member]
Revenue	$ 28,946	$ 28,701
Gross Profit	$ 3,961	$ 6,076
Gross Profit %	13.70%	21.20%
Corporate Segment [Member]
Revenue	$ 0	$ 0
Gross Profit	$ (257)	$ (310)