Gain (Loss) On Forgiveness Of Debt

No definition available.

Name:	efoi_GainLossOnForgivenessOfDebt
Namespace Prefix:	efoi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Payment Protection Program, Current

+ References

No definition available.

+ Details

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Namespace Prefix:	efoi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Payment Protection Program, Noncurrent

+ References

No definition available.

+ Details

Name:	efoi_PaymentProtectionProgramNoncurrent
Namespace Prefix:	efoi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Payroll Tax Credit, Employee Retention Credit Under The CARES Act

+ References

No definition available.

+ Details

Name:	efoi_PayrollTaxCreditEmployeeRetentionCreditUnderTheCARESAct
Namespace Prefix:	efoi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Payroll Tax Credit, Employee Retention Credit Under The CARES Act, Current

+ References

No definition available.

+ Details

Name:	efoi_PayrollTaxCreditEmployeeRetentionCreditUnderTheCARESActCurrent
Namespace Prefix:	efoi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 1B
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Cash inflow associated with loan origination (the process when securing a mortgage for a piece of real property) or lease origination.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3179-108585

+ Details

Name:	us-gaap_ProceedsFromLoanOriginations1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_DebtInstrumentAxis=efoi_PaycheckProtectionProgramCARESActMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Other Income (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
Other Income (Details) - USD ($) $ in Thousands	Apr. 17, 2020	Sep. 30, 2021	Dec. 31, 2021	Dec. 31, 2020	Jun. 30, 2021
Debt Instrument [Line Items]
ERTC refund		$ 431
ERTC expected receivable			$ 445	$ 0	$ 445
PPP loan			0	529
PPP loan, net of current maturities			0	266
Gain on forgiveness of PPP loan			801	0
Paycheck Protection Program CARES Act
Debt Instrument [Line Items]
Proceeds from loan origination	$ 795
Stated interest rate	1.00%
PPP loan				529
PPP loan, net of current maturities				$ 266
Gain on forgiveness of PPP loan			$ 801