The age of employees for contributions to become fully vested under deferred compensation arrangement.

No definition available.

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- Definition

The number of shares of the company's common stock owned by the plan.

+ References

No definition available.

+ Details

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- Definition

The compensation expense recognized during the period pertaining to the deferred compensation arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5047-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 710
-SubTopic 10
-Section 30
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=6409875&loc=d3e20015-108363

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- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements. Represents currently earned compensation under compensation arrangements that is not actually paid until a later date.

+ References

No definition available.

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- Definition

Carrying amount as of the balance sheet date of assets held under deferred compensation agreements.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(17))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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- Definition

Amount of cost for defined contribution plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 70
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942

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Note 12 - Retirement Fund and Profit Sharing Plan (Details Textual) $ in Millions	3 Months Ended
	Mar. 31, 2022 USD ($) shares	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)
Bel Fuse Inc. Employees' Savings Plan [Member]
Defined Contribution Plan, Cost	$ 0.4	$ 0.3
Bel Fuse Inc. Employees' Savings Plan [Member] \| Common Class A [Member]
Shares Held in Plan (in shares) \| shares	321,707
Bel Fuse Inc. Employees' Savings Plan [Member] \| Common Class B [Member]
Shares Held in Plan (in shares) \| shares	99,858
Nonqualified Deferred Compensation Plan [Member]
Deferred Compensation Arrangement, Vesting Age	65
Deferred Compensation Plan Assets	$ 0.7		$ 0.8
Deferred Compensation Liability, Current and Noncurrent, Total	0.7		$ 0.8
Nonqualified Deferred Compensation Plan [Member] \| Maximum [Member]
Deferred Compensation Arrangement with Individual, Compensation Expense	0.1	0.1
Retirement Fund Covering Hong Kong-based Employees [Member]
Defined Contribution Plan, Cost	$ 0.8	$ 0.1
Retirement Fund Covering Hong Kong-based Employees [Member] \| Common Class A [Member]
Shares Held in Plan (in shares) \| shares	3,323
Retirement Fund Covering Hong Kong-based Employees [Member] \| Common Class B [Member]
Shares Held in Plan (in shares) \| shares	17,342