XML 79 R67.htm IDEA: XBRL DOCUMENT v3.21.1

Fair Value of Assets and Liabilities - Significant Assumptions Used in Valuation of Level 3 Financial Instruments (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Impaired Loans (Collateral Dependent) | Minimum | Level 3 | Third Party Valuations
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired loans (collateral dependent)	0.00%	0.00%
Impaired Loans (Collateral Dependent) | Maximum | Level 3 | Third Party Valuations
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired loans (collateral dependent)	40.00%	40.00%
Impaired Loans (Collateral Dependent) | Weighted Average | Level 3 | Third Party Valuations
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired loans (collateral dependent)	20.00%	20.00%
Foreclosed Assets Held-for-sale | Minimum | Level 3 | Third Party Valuations
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired loans (collateral dependent)	0.00%	0.00%
Foreclosed Assets Held-for-sale | Maximum | Level 3 | Third Party Valuations
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired loans (collateral dependent)	40.00%	40.00%
Foreclosed Assets Held-for-sale | Weighted Average | Level 3 | Third Party Valuations
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired loans (collateral dependent)	35.00%	35.00%
Mortgage Servicing Rights | Minimum | Level 3 | Third Party Valuations
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights	242.00%	242.00%
Mortgage Servicing Rights | Maximum | Level 3 | Third Party Valuations
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights	438.00%	441.00%
Mortgage Servicing Rights | Weighted Average | Level 3 | Third Party Valuations
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Mortgage servicing rights	304.00%	384.00%
Fair Value, Nonrecurring | Impaired Loans (Collateral Dependent)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value	$ 12,733	$ 14,876
Fair Value, Nonrecurring | Foreclosed Assets Held-for-sale
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value	11,292	290
Fair Value, Nonrecurring | Mortgage Servicing Rights
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Assets, Fair Value	$ 551	$ 517

X

- Definition

Discount to reflect realizable value used when pricing the investments.

+ References

No definition available.

+ Details

Name:	fmbh_DiscountToReflectRealizableValue
Namespace Prefix:	fmbh_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Public securities association standard prepayment model rate.

+ References

No definition available.

+ Details

Name:	fmbh_PublicSecuritiesAssociationStandardPrepaymentModelRate
Namespace Prefix:	fmbh_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

+ Details

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

X

- 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_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_FairValueByAssetClassAxis=fmbh_ImpairedLoansCollateralDependentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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

X

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ValuationTechniqueAxis=us-gaap_MarketApproachValuationTechniqueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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

X

- Details

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

X

- Details

Name:	us-gaap_FairValueByAssetClassAxis=fmbh_ForeclosedAssetsHeldForSaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=fmbh_MortgageServicingRightsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsNonrecurringMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: