XML 10 R1.htm IDEA: XBRL DOCUMENT v3.22.2.2
Cover Page - shares
 9 Months Ended
Sep. 30, 2022
Oct. 26, 2022
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Sep. 30, 2022  
Document Transition Report false  
Entity File Number 0-18415  
Entity Registrant Name Isabella Bank Corp  
Entity Incorporation, State or Country Code MI  
Entity Tax Identification Number 38-2830092  
Entity Address, Address Line One 401 N. Main St  
Entity Address, City or Town Mt. Pleasant  
Entity Address, State or Province MI  
Entity Address, Postal Zip Code 48858  
City Area Code 989  
Local Phone Number 772-9471  
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  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   7,567,023
Current Fiscal Year End Date --12-31  
Entity Central Index Key 0000842517  
Document Fiscal Year Focus 2022  
Document Fiscal Period Focus Q3  
Amendment Flag false