XML 14 R1.htm IDEA: XBRL DOCUMENT v3.24.4
Document And Entity Information - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Mar. 28, 2024
Jun. 30, 2023
Document Information [Line Items]      
Entity, Registrant Name Middlefield Banc Corp.    
Current Fiscal Year End Date --12-31    
Document, Fiscal Period Focus FY    
Document, Fiscal Year Focus 2023    
Document, Type 10-K/A    
Document, Annual Report true    
Document, Period End Date Dec. 31, 2023    
Document, Transition Report false    
Entity, File Number 001-36613    
Entity, Incorporation, State or Country Code OH    
Entity, Tax Identification Number 34-1585111    
Entity, Address, Address Line One 15985 East High Street    
Entity, Address, City or Town Middlefield    
Entity, Address, State or Province OH    
Entity, Address, Postal Zip Code 44062-0035    
City Area Code 440    
Local Phone Number 632-1666    
Trading Symbol MBCN    
Title of 12(b) Security Common Stock, Without Par Value    
Security Exchange Name NASDAQ    
Entity, Well-known Seasoned Issuer No    
Entity, Voluntary Filers No    
Entity, Current Reporting Status Yes    
Entity, Interactive Data, Current Yes    
Entity, Filer Category Non-accelerated Filer    
Entity, Small Business true    
Entity, Emerging Growth Company false    
ICFR Auditor Attestation Flag false    
Document, Financial Statement Error Correction Flag false    
Entity, Shell Company false    
Entity, Public Float     $ 215.2
Entity, Common Stock Shares, Outstanding   8,069,144  
Amendment Description Middlefield Banc Corp (“Company”) is filing this Amendment No. 1 to its Annual Report on Form 10-K (“Form 10-K/A") for the fiscal year ended December 31, 2023, originally filed with the Securities and Exchange Commission (“SEC") on March 28, 2024 (“Original Filing”).   This Form 10-K/A is being filed to correct the Report of Independent Registered Public Accounting Firm of S. R. Snodgrass, P.C. included in the Original Filing due to an inadvertent administrative error. This Amendment does not alter in any way S. R. Snodgrass, P.C.’s opinion on the Company’s financial statements. This Form 10-K/A is also being filed to reflect correct dates in Management’s Annual Report on Internal Control Over Financial Reporting and amend wording in Item 9A(b).    In accordance with Rule 12b-15 under the Securities Exchange Act of 1934, as amended, certifications by the Company’s principal executive officer and principal financial officer are filed as exhibits to this Form 10-K/A under Item 15 of Part IV.  Additionally, this Form 10-K/A does not include the certifications under Section 906 of the Sarbanes-Oxley Act of 2002, as no financial statements are being filed with this Form 10-K/A.    Except as described above, this Form 10-K/A does not amend, modify, or otherwise update any other information in the Original Filing.  We have not updated or amended the disclosures contained in the Original Filing to reflect events that have occurred since the Original Filing.  Accordingly, this Form 10-K/A should be read in conjunction with our Original Filing.    
Auditor Name S. R. Snodgrass, P.C    
Auditor Location Cranberry Township, Pennsylvania    
Auditor Firm ID 74    
Amendment Flag true    
Entity, Central Index Key 0000836147