XML 71 R55.htm IDEA: XBRL DOCUMENT
v3.21.1

Fair Value Measurements and Disclosures - Financial assets measured at fair value on non-recurring basis (Details) - Nonrecurring - Level 3 - USD ($) $ in Thousands | Mar. 31, 2021 | Dec. 31, 2020
--- | --- | ---
Financial assets measured at fair value on a nonrecurring basis |  |
Mortgage servicing rights | $ 7,118 | $ 4,647
SBA loan servicing rights | 1,160 | 970
Impaired loans | 3,550 | 2,998
Total | $ 11,828 | $ 8,615

X
- Definition Fair value of impaired loans. + References No definition available. + Details
Name: | mrbk_ImpairedLoansFairValueDisclosure
Namespace Prefix: | mrbk_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of mortgage servicing rights. + References No definition available. + Details
Name: | mrbk_MortgageServiceRightsFairValueDisclosure
Namespace Prefix: | mrbk_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of Small Business Administration (SBA) loan servicing rights. + References No definition available. + Details
Name: | mrbk_SmallBusinessAdministrationLoanServicingRights
Namespace Prefix: | mrbk_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsNonrecurringMember
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: |