Leases - Schedule of Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Operating Leases
Operating lease, right-of-use asset	$ 1,034	$ 1,180
Operating lease liabilities	1,125	1,227
Finance Leases
Property and equipment	13	13
Allowances for depreciation	(13)	(13)
Finance lease assets, net	$ 0	$ 0

Finance Lease, Assets And Liabilities, Lessee

No definition available.

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- Definition

Finance Lease, Right-Of-Use Asset, Accumulated Depreciation

+ References

No definition available.

+ Details

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- Definition

Finance Lease, Right-Of-Use Asset, Gross

+ References

No definition available.

+ Details

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

- Definition

Operating Lease, Assets And Liabilities, Lessee

+ References

No definition available.

+ Details

Name:	efoi_OperatingLeaseAssetsAndLiabilitiesLesseeAbstract
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- Definition

Amount, after accumulated amortization, of right-of-use asset from finance lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479041/842-20-45-1

+ Details

Name:	us-gaap_FinanceLeaseRightOfUseAsset
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Present value of lessee's discounted obligation for lease payments from operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479041/842-20-45-1

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Amount of lessee's right to use underlying asset under operating lease.

+ References

+ Details

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Balance Type:	debit
Period Type:	instant