Business combination consideration allowance for credit losses.

No definition available.

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Namespace Prefix:	fmbh_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Business combination, consideration allowance for credit losses on non-PCD loans.

+ References

No definition available.

+ Details

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Namespace Prefix:	fmbh_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479907/805-20-50-5

+ Details

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Period Type:	duration

- Definition

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

+ References

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-Topic 805
-SubTopic 10
-Section 25
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-Publisher FASB
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Balance Type:	debit
Period Type:	duration

- Definition

The number of new shares issued in the conversion of stock in a noncash (or part noncash) transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

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-Topic 230
-SubTopic 10
-Section 50
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-Section 50
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-Publisher FASB
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Balance Type:	na
Period Type:	duration

- Definition

Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 350
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 24
-Publisher FASB
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-URI https://asc.fasb.org/1943274/2147482573/350-20-50-1

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Business Combinations - Additional Information (Details) - Blackhawk Bancorp, Inc - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Mar. 20, 2023	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Business Acquisition [Line Items]
Conversion of common stock	1.15
Goodwill acquired during period	$ 50,100		$ 50,100
Pre-tax of acquisition costs		$ 100	$ 2,100	$ 2,500	$ 2,600
ASU 2016-13
Business Acquisition [Line Items]
Allowance for credit losses	3,800
Allowance for credit losses on non-PCD loans	$ 618,330
Core Deposit Intangibles
Business Acquisition [Line Items]
Intangible asset estimated useful life	10 years