Note 13 - Assets Held for Sale and Discontinued Operations (Details Textual) - Nestor Cables [Member] - USD ($)		3 Months Ended
Nov. 11, 2025	Sep. 30, 2025
Proceeds from Divestiture of Businesses and Interests in Affiliates	$ 1
Discontinued Operation, Provision for Loss (Gain) on Disposal, before Income Tax		$ 16,589,000
Disposal Group, Including Discontinued Operations, Goodwill Impairment		2,022,000
Disposal Group, Including Discontinued Operation, Impairment of Long-lived Assets		$ 13,078,000

Total loss recognized during the period from the impairment of long-lived assets attributable to a disposal group.

No definition available.

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Balance Type:	debit
Period Type:	duration

- Definition

Total loss recognized during the period from the impairment of goodwill attributable to a disposal group.

+ References

No definition available.

+ Details

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Namespace Prefix:	clfd_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount before tax of (gain) loss recognized for the (reversal of write-down) write-down to fair value, less cost to sell, of a discontinued operation.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 205
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5C
-Subparagraph (b)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483499/205-20-50-5C

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 205
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483499/205-20-50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 205
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 3B
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483475/205-20-45-3B

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 205
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483475/205-20-45-3

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash inflow associated with the amount received from the sale of a business segment or subsidiary or sale of an entity that is related to it but not strictly controlled during the period (for example, an unconsolidated subsidiary, affiliate, joint venture or equity method investment).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-12

+ Details

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Data Type:	xbrli:monetaryItemType
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- Details

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