Debt Instrument, Base Rate, Variable

No definition available.

Name:	efoi_DebtInstrumentBaseRateVariable
Namespace Prefix:	efoi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Interest Rate, Stated Percentage, Collateral Management Fee

+ References

No definition available.

+ Details

Name:	efoi_DebtInstrumentInterestRateStatedPercentageCollateralManagementFee
Namespace Prefix:	efoi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Instrument, Number Of Credit Facilities

+ References

No definition available.

+ Details

Name:	efoi_DebtInstrumentNumberOfCreditFacilities
Namespace Prefix:	efoi_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Line of Credit Facility, Borrowing Capacity, Inventory Costs, Percent

+ References

No definition available.

+ Details

Name:	efoi_LineOfCreditFacilityBorrowingCapacityInventoryCostsPercent
Namespace Prefix:	efoi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line of Credit Facility, Borrowing Capacity, Inventory Value, Percent

+ References

No definition available.

+ Details

Name:	efoi_LineOfCreditFacilityBorrowingCapacityInventoryValuePercent
Namespace Prefix:	efoi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line of Credit Facility, Borrowing Capacity, Value Of Accounts Receivable, Percent

+ References

No definition available.

+ Details

Name:	efoi_LineOfCreditFacilityBorrowingCapacityValueOfAccountsReceivablePercent
Namespace Prefix:	efoi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line Of Credit Facility, Monthly Facility Fee

+ References

No definition available.

+ Details

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

- Definition

Line Of Credit Facility, Monthly Facility Fee, Percent

+ References

No definition available.

+ Details

Name:	efoi_LineOfCreditFacilityMonthlyFacilityFeePercent
Namespace Prefix:	efoi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- 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 https://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 https://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

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current portion of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(13))
-URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878

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(19))
-URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_LinesOfCreditCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_VariableRateAxis=efoi_WallStreetJournalHighestPrimeRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Debt - Credit Facilities (Details)	Aug. 11, 2020 USD ($) creditFacility	Jan. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Apr. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Debt Instrument [Line Items]
Number of new credit facilities \| creditFacility	2
Credit line borrowings, net of loan origination fees			$ 1,447,000		$ 2,169,000
Revolving Credit Facility \| Inventory Facility
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity	$ 3,000,000			$ 3,500,000
Inventory costs	75.00%
Inventory, net orderly liquidation value	85.00%
Interest rate	5.75%		25.50%		22.40%
Monthly service fee	1.00%
Minimum monthly fee	$ 18,000
Credit line borrowings, net of loan origination fees			$ 1,400,000		$ 1,200,000
Unamortized net issuance costs			$ 47,000		$ 84,000
Revolving Credit Facility \| Inventory Facility \| Subsequent Event
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity		$ 500,000
Revolving Credit Facility \| Inventory Facility \| London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Interest rate	4.00%
Variable interest rate, base			4.77%		0.21%
Revolving Credit Facility \| Receivables Facility
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity	$ 2,500,000
Interest rate	2.00%		10.10%		8.00%
Monthly service fee	1.00%
Minimum monthly fee	$ 25,000
Percent of accounts receivable used as borrowing capacity	90.00%
Stated interest rate on collateral management fee			6.30%		5.90%
Credit line borrowings, net of loan origination fees			$ 100,000		$ 1,000,000.0
Unamortized net issuance costs			$ 15,000		$ 24,000
Revolving Credit Facility \| Receivables Facility \| Wall Street Journal, highest prime rate
Debt Instrument [Line Items]
Variable interest rate, base			7.50%		3.25%