XML 105 R95.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Repurchase Agreements and Other Borrowings - Additional Information (Details) |  |  |  |  |  | 12 Months Ended |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Sep. 06, 2024 USD ($) | Aug. 27, 2024 USD ($) | Jun. 07, 2024 USD ($) | Aug. 15, 2023 USD ($) Quarters shares | Oct. 06, 2020 USD ($) | Dec. 31, 2024 USD ($) | Dec. 31, 2023 USD ($) | Dec. 31, 2021 USD ($) | May 01, 2018 USD ($) | Sep. 08, 2016 USD ($) | Dec. 31, 2007 USD ($) | Apr. 26, 2006 USD ($)
Repurchase Agreements And Other Borrowings [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Federal Home Loan Bank Advances |  |  |  |  |  | $ 242,400,000 |  |  |  |  |  |
Securities sold under agreements to repurchase weighted average rate |  |  |  |  |  | 2.28% |  |  |  |  |  |
Subordinated Debentures |  |  |  |  |  | $ 87,472,000 | $ 106,755,000 |  |  |  |  |
Junior subordinated debentures, net |  |  |  |  |  | 24,280,000 | $ 24,058,000 |  |  |  |  |
Junior Subordinated Debentures |  |  |  |  |  |  |  |  |  |  |  |
Repurchase Agreements And Other Borrowings [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount issued and outstanding |  |  |  |  |  | 25,775,000 |  |  |  |  |  |
Junior subordinated debentures, net |  |  |  |  |  | 24,280,000 |  |  |  |  |  |
3.95% Subordinated Notes due 2030 |  |  |  |  |  |  |  |  |  |  |  |
Repurchase Agreements And Other Borrowings [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  |  | $ 96,000,000.0 |  |  |  |  |  |  |
Shares repurchased and subsequently cancelled | $ 1,000,000 | $ 15,000,000 | $ 4,000,000 |  |  |  |  |  |  |  |  |
Aggregate principal amount issued and outstanding |  |  |  |  |  | $ 76,000,000 |  |  |  |  |  |
Fixed-to-Floating Rate |  |  |  |  | 3.95% |  |  |  |  |  |  |
Maturity date |  |  |  |  | Oct. 15, 2030 |  |  |  |  |  |  |
Description floating rate basis |  |  |  |  |  | three-month Term SOFR |  |  |  |  |  |
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration] |  |  |  |  |  | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] |  |  |  |  |  |
Basis points |  |  |  |  | 3.83% |  |  |  |  |  |  |
Redemption description |  |  |  |  |  | The Company may, beginning with the interest payment date of October 15, 2025, and on any interest payment date thereafter, redeem the Notes, in whole or in part, at a redemption price equal to 100% of the principal amount of the Notes to be redeemed plus accrued and unpaid interest to but excluding the date of redemption. The Company may also redeem the Notes at any time, including prior to October 15, 2025, at the Company’s option, in whole but not in part, if: (i) a change or prospective change in law occurs that could prevent the Company from deducting interest payable on the Notes for U.S. federal income tax purposes; (ii) a subsequent event occurs that could preclude the Notes from being recognized as Tier 2 capital for regulatory capital purposes; or (iii) the Company is required to register as an investment company under the Investment Company Act of 1940, as amended; in each case, at a redemption price equal to 100% of the principal amount of the Notes plus any accrued and unpaid interest to but excluding the redemption date. |  |  |  |  |  |
FMIS Trust II |  |  |  |  |  |  |  |  |  |  |  |
Repurchase Agreements And Other Borrowings [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Trust preferred securities issued |  |  |  |  |  |  |  |  |  |  |  | $ 10,000,000
Investment in statutory trust |  |  |  |  |  |  |  |  |  |  |  | $ 310,000
Junior subordinated debentures, net |  |  |  |  |  |  |  | $ 10,300,000 |  |  |  |
FMIS Trust II | Junior Subordinated Debentures |  |  |  |  |  |  |  |  |  |  |  |
Repurchase Agreements And Other Borrowings [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Fixed-to-Floating Rate |  |  |  |  |  | 6.81% | 7.25% |  |  |  |  |
Debt instrument, interest rate terms |  |  |  |  |  | bore interest at a fixed rate of 6.98% paid quarterly until June 15, 2011 and then converted to floating rate (LIBOR plus 160 basis points) after June 15, 2011 |  |  |  |  |  |
BHS Trust I |  |  |  |  |  |  |  |  |  |  |  |
Repurchase Agreements And Other Borrowings [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number of consecutive quarters that interest payments on subordinated debentures may be deferred | Quarters |  |  |  | 20 |  |  |  |  |  |  |  |
Fixed-to-Floating Rate |  |  |  |  |  | 8.17% | 8.87% |  |  |  |  |
Basis points |  |  |  | 3.25% |  |  |  |  |  |  |  |
Preferred and Common Ownership Shares Issued |  |  |  | 100.00% |  |  |  |  |  |  |  |
Subordinated Debentures |  |  |  | $ 7,200,000 |  |  |  |  |  |  |  |
Redeeemed Subordinated Debentures |  |  |  |  |  |  |  |  |  |  | $ 6,200,000 |
Common Ownership Shares | shares |  |  |  | 217,000 |  |  |  |  |  |  |  |
Trust preferred securities issued |  |  |  | $ 7,000,000 |  |  |  |  |  |  |  |
Debt instrument, interest rate terms |  |  |  |  |  | three-month LIBOR |  |  |  |  |  |
BHS Trust II |  |  |  |  |  |  |  |  |  |  |  |
Repurchase Agreements And Other Borrowings [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number of consecutive quarters that interest payments on subordinated debentures may be deferred | Quarters |  |  |  | 20 |  |  |  |  |  |  |  |
Fixed-to-Floating Rate |  |  |  |  |  | 7.25% | 7.69% |  |  |  |  |
Basis points |  |  |  | 2.05% |  |  |  |  |  |  |  |
Preferred and Common Ownership Shares Issued |  |  |  | 100.00% |  |  |  |  |  |  |  |
Subordinated Debentures |  |  |  | $ 4,100,000 |  |  |  |  |  |  |  |
Common Ownership Shares | shares |  |  |  | 124,000 |  |  |  |  |  |  |  |
Trust preferred securities issued |  |  |  | $ 4,000,000 |  |  |  |  |  |  |  |
Debt instrument, interest rate terms |  |  |  |  |  | three-month LIBOR |  |  |  |  |  |
CLS Trust I |  |  |  |  |  |  |  |  |  |  |  |
Repurchase Agreements And Other Borrowings [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Trust preferred securities issued |  |  |  |  |  |  |  |  |  | $ 4,000,000.0 |  |
Investment in statutory trust |  |  |  |  |  |  |  |  |  | $ 124,000 |  |
CLS Trust I | Junior Subordinated Debentures |  |  |  |  |  |  |  |  |  |  |  |
Repurchase Agreements And Other Borrowings [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Fixed-to-Floating Rate |  |  |  |  |  | 7.06% | 7.50% |  |  |  |  |
Debt instrument, interest rate terms |  |  |  |  |  | bear interest at three-month LIBOR plus 185 basis points |  |  |  |  |  |
FBTCST I |  |  |  |  |  |  |  |  |  |  |  |
Repurchase Agreements And Other Borrowings [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Trust preferred securities issued |  |  |  |  |  |  |  |  | $ 6,000,000.0 |  |  |
Investment in statutory trust |  |  |  |  |  |  |  |  | $ 186,000 |  |  |
FBTCST I | Junior Subordinated Debentures |  |  |  |  |  |  |  |  |  |  |  |
Repurchase Agreements And Other Borrowings [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Fixed-to-Floating Rate |  |  |  |  |  | 6.91% | 7.35% |  |  |  |  |
Debt instrument, interest rate terms |  |  |  |  |  | bear interest at three-month LIBOR plus 170 basis points |  |  |  |  |  |
Blackhawk |  |  |  |  |  |  |  |  |  |  |  |
Repurchase Agreements And Other Borrowings [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  | $ 15,000,000 |  |  |  |  |  |  |  |
Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed |  |  |  | 100.00% |  |  |  |  |  |  |  |
Blackhawk | 3.50% |  |  |  |  |  |  |  |  |  |  |  |
Repurchase Agreements And Other Borrowings [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  | $ 7,500,000 |  |  |  |  |  |  |  |
Interest rate (as a percent) |  |  |  | 3.50% |  |  |  |  |  |  |  |
Debt instrument, maturity month and year |  |  |  | 2031-05 |  |  |  |  |  |  |  |
Description floating rate basis |  |  |  |  |  | three-month SOFR |  |  |  |  |  |
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration] |  |  |  |  |  | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] |  |  |  |  |  |
Basis points |  |  |  | 2.85% |  |  |  |  |  |  |  |
Blackhawk | 3.875% |  |  |  |  |  |  |  |  |  |  |  |
Repurchase Agreements And Other Borrowings [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount |  |  |  | $ 7,500,000 |  |  |  |  |  |  |  |
Interest rate (as a percent) |  |  |  | 3.875% |  |  |  |  |  |  |  |
Debt instrument, maturity month and year |  |  |  | 2036-05 |  |  |  |  |  |  |  |
Description floating rate basis |  |  |  | three-month SOFR |  |  |  |  |  |  |  |
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration] |  |  |  | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] |  |  |  |  |  |  |  |
Basis points |  |  |  | 2.55% |  |  |  |  |  |  |  |
Revolving Credit Facility |  |  |  |  |  |  |  |  |  |  |  |
Repurchase Agreements And Other Borrowings [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Line of credit facility, maximum borrowing capacity |  |  |  |  |  | $ 15,000,000 |  |  |  |  |  |
Line of credit facility, interest rate spread |  |  |  |  |  | 2.25% |  |  |  |  |  |

X
- Definition Common ownership shares. + References No definition available. + Details
Name: | fmbh_CommonOwnershipShares
Namespace Prefix: | fmbh_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Short-term and long-term Federal Home Loan Bank borrowings. + References No definition available. + Details
Name: | fmbh_FederalHomeLoanBankAdvancesShortAndLongTerm
Namespace Prefix: | fmbh_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Investment in common equity of Statutory Trust + References No definition available. + Details
Name: | fmbh_InvestmentInStatutoryTrust
Namespace Prefix: | fmbh_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of interest rate spread over federal funds rate. + References No definition available. + Details
Name: | fmbh_LineOfCreditFacilityInterestRateSpread
Namespace Prefix: | fmbh_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of consecutive quarters that interest payments on subordinated debentures may be deferred. + References No definition available. + Details
Name: | fmbh_NumberOfConsecutiveQuartersThatInterestPaymentsOnSubordinatedDebenturesMayBeDeferred
Namespace Prefix: | fmbh_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Preferred and common ownership shares issued. + References No definition available. + Details
Name: | fmbh_PreferredAndCommonOwnershipSharesIssued
Namespace Prefix: | fmbh_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Redeeemed Subordinated Debentures + References No definition available. + Details
Name: | fmbh_RedeeemedSubordinatedDebentures
Namespace Prefix: | fmbh_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Repurchase agreements and other borrowings. + References No definition available. + Details
Name: | fmbh_RepurchaseAgreementsAndOtherBorrowingsLineItems
Namespace Prefix: | fmbh_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Securities Sold Under Agreements to Repurchase Weighted Average Rate + References No definition available. + Details
Name: | fmbh_SecuritiesSoldUnderAgreementsToRepurchaseWeightedAverageRate
Namespace Prefix: | fmbh_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Trust preferred securities issued and sold through a statutory trust as part of a pooled offering + References No definition available. + Details
Name: | fmbh_TrustPreferredSecuritiesIssued
Namespace Prefix: | fmbh_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The month and year (YYYY-MM) in which the original debt was scheduled to mature. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482913/230-10-50-3 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482913/230-10-50-5 + Details
Name: | us-gaap_DebtConversionOriginalDebtDueDateOfDebtMonthAndYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:gYearMonthItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Description of reference rate used for variable rate of debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentDescriptionOfVariableRateBasis
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 835 -SubTopic 30 -Name Accounting Standards Codification -Section 55 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482949/835-30-55-8 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 69B -Publisher FASB -URI https://asc.fasb.org/1943274/2147481568/470-20-55-69B Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 69C -Publisher FASB -URI https://asc.fasb.org/1943274/2147481568/470-20-55-69C Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 835 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482900/835-30-50-1 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 835 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482925/835-30-45-2 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 835 -SubTopic 30 -Name Accounting Standards Codification -Section 55 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482949/835-30-55-8 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)(a)(1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 835 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482900/835-30-50-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 835 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482925/835-30-45-2 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-6 + Details
Name: | us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)(a)(1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Description of the interest rate as being fixed or variable, and, if variable, identification of the index or rate on which the interest rate is based and the number of points or percentage added to that index or rate to set the rate, and other pertinent information, such as frequency of rate resets. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)(a)(1)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_DebtInstrumentInterestRateTerms
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date when the debt instrument is scheduled to be fully repaid, in YYYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(2)(i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)(a)(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B + Details
Name: | us-gaap_DebtInstrumentMaturityDate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Description of debt redemption features under terms of the debt agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 470 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477734/942-470-50-3 + Details
Name: | us-gaap_DebtInstrumentRedemptionDescription
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of principal amount of debt redeemed. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Indicates type of variable interest rate on debt instrument. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 942 -SubTopic 470 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477734/942-470-50-3 + Details
Name: | us-gaap_DebtInstrumentVariableInterestRateTypeExtensibleEnumeration
Namespace Prefix: | us-gaap_
Data Type: | enum2:enumerationSetItemType
Balance Type: | na
Period Type: | duration

X
- Definition Including the current and noncurrent portions, the carrying value of junior subordinated long-term debt owed to unconsolidated subsidiary trusts as of the balance sheet date. Such debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets and was initially scheduled to be repaid after one year or beyond the normal operating cycle if longer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)(a)(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 + Details
Name: | us-gaap_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- 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 Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(19)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -SubTopic 10 -Topic 210 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 835 -SubTopic 30 -Name Accounting Standards Codification -Section 55 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482949/835-30-55-8 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1 Reference 4: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 69B -Publisher FASB -URI https://asc.fasb.org/1943274/2147481568/470-20-55-69B Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 69C -Publisher FASB -URI https://asc.fasb.org/1943274/2147481568/470-20-55-69C Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1D -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-1D Reference 7: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)(a)(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 470 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (b)(3) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481139/470-20-50-4 + Details
Name: | us-gaap_LongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Equity impact of the value of stock that has been repurchased and retired during the period. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -SubTopic 10 -Topic 505 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481112/505-10-50-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1 + Details
Name: | us-gaap_StockRepurchasedAndRetiredDuringPeriodValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Including the current and noncurrent portions, carrying value as of the balance sheet date of subordinated debt (with initial maturities beyond one year or beyond the operating cycle if longer). Subordinated debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -SubTopic 10 -Topic 210 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(19)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)(a)(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478777/944-210-S99-1 + Details
Name: | us-gaap_SubordinatedDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_JuniorSubordinatedDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fmbh_ThreePointNineFivePercentSubordinatedNotesDueTwoThousandThirtyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fmbh_FmisTrustIiMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fmbh_BhsTrustIMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fmbh_BhsTrustIiMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fmbh_CLSTrustIMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fmbh_FBTCSTIMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=fmbh_BlackhawkMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fmbh_ThreePointFiveZeroPercentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=fmbh_ThreePointEightSevenFivePercentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |