XML 96 R101.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Derivatives Derivative Insturments, Gain (Loss) (Details) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2019 USD ($)
Derivative Instruments, Gain (Loss) [Abstract] |
Gain (Loss) on Derivative | $ (325)
Gain (Loss) on Hedged Items | $ 325

X
- Definition Derivative Instruments, Gain (Loss) [Abstract] + References No definition available. + Details
Name: | fmbh_DerivativeInstrumentsGainLossAbstract
Namespace Prefix: | fmbh_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 25 -Section 50 -Paragraph 1 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=109977999&loc=d3e76258-113986 + Details
Name: | us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5618551-113959 + Details
Name: | us-gaap_DerivativeGainLossOnDerivativeNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration