Note 11 - Recent Accounting Pronouncements (Details Textual) $ in Millions	Mar. 31, 2021 USD ($)
Number of Purchased Participation Loans Tied to LIBOR Reference Rate	14
Purchased Participation Loans Tied to LIBOR Reference Rate, Outstanding Balance	$ 42.5
Number of Tax-exempt Loans Tied to LIBOR Reference Rate	2
Tax-exempt Loans Tied to LIBOR Reference Rate, Outstanding Balance	$ 2.5

The outstanding balance of purchased participation loans that are tied to LIBOR reference rate.

No definition available.

Name:	emcf_PurchasedParticipationLoansTiedToLIBORReferenceRateOutstandingBalance
Namespace Prefix:	emcf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant