Note 8 - Deposits - Scheduled Maturities of Time Deposits $250,000 or More (Details) $ in Thousands	Dec. 31, 2020 USD ($)
Three months or less	$ 6,894
Over three months to six months	3,902
Over six months to twelve months	20,538
Over twelve months	27,374
Total	$ 58,708

Amount of time deposits above $250,000 maturing in three months through six months.

No definition available.

Name:	emcf_ContractualMaturitiesTimeDeposits250000OrMoreThreeMonthsThroughSixMonths
Namespace Prefix:	emcf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant