The percentage of eligible receivables which determines the amount of line of credit available.

No definition available.

Name:	efoi_LineOfCreditFacilityAvailablePercentageOfReceivables
Namespace Prefix:	efoi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The threshold for determining the available line of credit with regards to the lessor of the percentage of lower of cost or market value of inventory or a predetermined value.

+ References

No definition available.

+ Details

Name:	efoi_LineOfCreditFacilityAvailableThresholdPercent
Namespace Prefix:	efoi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The threshold for determining the available line of credit with regards to the lessor of the percentage of lower of cost or market value of inventory or a predetermined value.

+ References

No definition available.

+ Details

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

- Definition

Line Of Credit Facility, Overdraft Fee Percentage

+ References

No definition available.

+ Details

Name:	efoi_LineOfCreditFacilityOverdraftFeePercentage
Namespace Prefix:	efoi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of Credit Facility, Minimum Borrowing Capacity

+ References

No definition available.

+ Details

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

- Definition

Right To Terminate, Liquidated Damages, Year One, Percent

+ References

No definition available.

+ Details

Name:	efoi_RightToTerminateLiquidatedDamagesYearOnePercent
Namespace Prefix:	efoi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Right To Terminate, Liquidated Damages, Year Three, Percent

+ References

No definition available.

+ Details

Name:	efoi_RightToTerminateLiquidatedDamagesYearThreePercent
Namespace Prefix:	efoi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Right To Terminate, Liquidated Damages, Year Two, Percent

+ References

No definition available.

+ Details

Name:	efoi_RightToTerminateLiquidatedDamagesYearTwoPercent
Namespace Prefix:	efoi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Right to Terminate, Notice Required, Period of Time

+ References

No definition available.

+ Details

Name:	efoi_RighttoTerminateNoticeRequiredPeriodofTime
Namespace Prefix:	efoi_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ 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 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num: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

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The effective interest rate during the reporting period.

+ 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 http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateDuringPeriod
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
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 http://asc.fasb.org/extlink&oid=6877327&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 http://asc.fasb.org/extlink&oid=6876686&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 http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Details

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

- Details

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

Debt - Credit Facilities (Details) - USD ($)		12 Months Ended
Debt - Credit Facilities (Details) - USD ($)	Dec. 11, 2018	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Borrowings		$ 2,219,000	$ 0
Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility, term	3 years
Credit facility, maximum borrowing capacity	$ 5,000,000.0
Credit facility, available percentage of receivables	85.00%
Credit facility, available threshold, percent	50.00%
Credit facility, available threshold	$ 500,000
Credit facility, minimum borrowing capacity	$ 1,000,000.0
Credit facility, interest rate	0.50%	7.75%
Credit facility, overdraft fee percentage	2.00%
Stated interest rate	1.00%
Right to terminate, notice required, period of time	90 days
Right to terminate, liquidated damages, year one, percent	3.00%
Right to terminate, liquidated damages, year two, percent	2.00%
Right to terminate, liquidated damages, year three, percent	1.00%
Borrowings		$ 2,200,000
Prime Rate \| Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility, basis spread on variable rate	2.00%