Note 9 - Borrowed Funds (Details Textual) $ in Thousands	12 Months Ended
Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Long-term Line of Credit, Total	$ 0	$ 0
Long-term Debt, Total	30,000	$ 26,500
Loans from Other Federal Home Loan Banks	30,000
Deposits with Other Federal Home Loan Banks	137,700
Federal Home Loan Bank, Advances, General Debt Obligations, Maximum Amount Available	$ 268,600
Federal Home Loan Bank Advances, Maturing 2021 to 2025 [Member]
Federal Home Loan Bank Advances, Number of Advances Outstanding	6
Federal Home Loan Bank, Advances, Par Value, Total	$ 30,000
Federal Home Loan Bank Advances, Maturing 2021 to 2025 [Member] \| Minimum [Member]
Federal Home Loan Bank, Advances, Interest Rate	0.97%
Federal Home Loan Bank Advances, Maturing 2021 to 2025 [Member] \| Maximum [Member]
Federal Home Loan Bank, Advances, Interest Rate	2.85%
Federal Home Loan Bank Advances, Maturing 2021 to 2025, Advance 1 [Member]
Federal Home Loan Bank, Advances, Par Value, Total	$ 5,000
Federal Home Loan Bank Advances, Maturing 2020 to 2023 [Member]
Federal Home Loan Bank Advances, Number of Advances Outstanding		5
Federal Home Loan Bank, Advances, Par Value, Total		$ 25,000
Federal Home Loan Bank Advances, Maturing 2020 to 2023, Advance 1 [Member]
Federal Home Loan Bank, Advances, Par Value, Total		5,000
Federal Home Loan Bank Advances, Maturing 2020 to 2023, Advance 5 [Member]
Federal Home Loan Bank, Advances, Par Value, Total		5,000
Federal Home Loan Bank Advances, Maturing 2020 to 2023, Advance 4 [Member]
Federal Home Loan Bank, Advances, Par Value, Total		5,000
Federal Home Loan Bank Advances, Maturing 2020 to 2023, Advance 3 [Member]
Federal Home Loan Bank, Advances, Par Value, Total		5,000
Federal Home Loan Bank Advances, Maturing 2020 to 2023, Advance 2 [Member]
Federal Home Loan Bank, Advances, Par Value, Total		5,000
Unsecured Term Loan [Member]
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Collateral Pledged	$ 436,300
Debt Instrument, Term (Year)	5 years
Long-term Debt, Total		1,500
Federal Home Loan Bank Advances, Maturing 2021 to 2025, Advance 3 [Member]
Federal Home Loan Bank, Advances, Par Value, Total	$ 5,000
Federal Home Loan Bank Advances, Maturing 2021 to 2025, Advance 2 [Member]
Federal Home Loan Bank, Advances, Par Value, Total	5,000
Federal Home Loan Bank Advances, Maturing 2021 to 2025, Advance 4 [Member]
Federal Home Loan Bank, Advances, Par Value, Total	5,000
Federal Home Loan Bank Advances, Maturing 2021 to 2025, Advance 5 [Member]
Federal Home Loan Bank, Advances, Par Value, Total	5,000
Federal Home Loan Bank Advances, Maturing 2021 to 2025, Advance 6 [Member]
Federal Home Loan Bank, Advances, Par Value, Total	5,000
Line of Credit [Member]
Long-term Line of Credit, Total	2,100	2,100
Line of Credit Facility, Maximum Borrowing Capacity	$ 4,500	$ 7,000
Debt Instrument, Interest Rate, Stated Percentage	4.25%	5.00%
Line of Credit Facility, Remaining Borrowing Capacity	$ 2,400

The number of outstanding federal home loan bank advances.

No definition available.

Name:	emcf_FederalHomeLoanBankAdvancesNumberOfAdvancesOutstanding
Namespace Prefix:	emcf_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

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

+ References

+ Details

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

- 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

Amount of interest-bearing funds deposited into another Federal Home Loan Banks (FHLBanks).

+ References

No definition available.

+ Details

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

- Definition

Amount of the collateral pledged in support of federal home loan bank advances outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

+ Details

Name:	us-gaap_FederalHomeLoanBankAdvancesGeneralDebtObligationsDisclosuresCollateralPledged1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of maximum advances or credit lines available from the Federal Home Loan Bank (FHLB).

+ 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(3)(a))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822

Reference 3: 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 (b))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Definition

Interest rate of advances made and reported by Federal Home Loan Bank (FHLBank).

+ References

No definition available.

+ Details

Name:	us-gaap_FederalHomeLoanBankAdvancesInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Par amount of advances made and reported by Federal Home Loan Bank (FHLBank).

+ References

No definition available.

+ Details

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

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions 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 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: 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(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

+ Details

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

- 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

+ Details

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

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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

- Definition

Amount of Federal Home Loan Bank (FHLBank) loans from another FHLBank.

+ References

No definition available.

+ Details

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

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Reference 3: 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(16))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 4: 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))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=emcf_FederalHomeLoanBankAdvancesMaturing2021To2025Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=emcf_FederalHomeLoanBankAdvancesMaturing2021To2025Advance1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=emcf_FederalHomeLoanBankAdvancesMaturing2020To2023Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=emcf_FederalHomeLoanBankAdvancesMaturing2020To2023Advance1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=emcf_FederalHomeLoanBankAdvancesMaturing2020To2023Advance5Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=emcf_FederalHomeLoanBankAdvancesMaturing2020To2023Advance4Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=emcf_FederalHomeLoanBankAdvancesMaturing2020To2023Advance3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=emcf_FederalHomeLoanBankAdvancesMaturing2020To2023Advance2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=emcf_FederalHomeLoanBankAdvancesMaturing2021To2025Advance3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=emcf_FederalHomeLoanBankAdvancesMaturing2021To2025Advance2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=emcf_FederalHomeLoanBankAdvancesMaturing2021To2025Advance4Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=emcf_FederalHomeLoanBankAdvancesMaturing2021To2025Advance5Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=emcf_FederalHomeLoanBankAdvancesMaturing2021To2025Advance6Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShortTermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: