XML 98 R89.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Deposits - Additional Information (Details) - USD ($) $ in Millions | Dec. 31, 2023 | Dec. 31, 2022
--- | --- | ---
Demand deposits: |  |
Total of Public entitiy balances | $ 381.3 | $ 319.4

X
- Definition Total balance of Public entities with large balances + References No definition available. + Details
Name: | fmbh_TotalOfPublicEntitiyBalances
Namespace Prefix: | fmbh_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_DepositsByTypeAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration