XML 55 R45.htm IDEA: XBRL DOCUMENT v3.25.3
Capital Ratios and Shareholders' Equity - Compliance with Regulatory Capital Requirements (Details)
$ in Thousands
Sep. 30, 2025
USD ($)
Dec. 31, 2024
USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]    
Common equity Tier 1 capital to risk weighted assets, Actual, Amount $ 189,547 $ 183,348
Common equity Tier 1 capital to risk weighted assets, Actual, Ratio 0.1237 0.1221
Common equity Tier 1 capital to risk weighted assets, Minimum Capital Required Plus Capital Conservation Buffer, Amount $ 107,266 $ 105,136
Common equity Tier 1 capital to risk weighted assets, Minimum Capital Required Plus Capital Conservation Buffer, Ratio 7.00% 7.00%
Tier 1 capital to risk weighted assets, Actual, Amount $ 189,547 $ 183,348
Tier 1 capital to risk weighted assets, Actual, Ratio 0.1237 0.1221
Tier 1 capital to risk weighted assets, Minimum Capital Required Plus Capital Conservation Buffer, Amount $ 130,251 $ 127,665
Tier 1 capital to risk weighted assets, Minimum Capital Required Plus Capital Conservation Buffer, Ratio 0.0850 0.0850
Total capital to risk weighted assets, Actual, Amount $ 232,859 $ 226,179
Total capital to risk weighted assets, Actual, Ratio 0.1520 0.1506
Total capital to risk weighted assets, Minimum Capital Required Plus Capital Conservation Buffer, Amount $ 160,898 $ 157,703
Total capital to risk weighted assets, Minimum Capital Required Plus Capital Conservation Buffer, Ratio 0.1050 0.1050
Tier 1 capital to average assets, Actual, Amount $ 189,547 $ 183,348
Tier 1 capital to average assets, Actual, Ratio 0.0871 0.0886
Tier 1 capital to average assets, Minimum Capital Required Plus Capital Conservation Buffer, Amount $ 87,019 $ 82,803
Tier 1 capital to average assets, Minimum Capital Required Plus Capital Conservation Buffer, Ratio 0.0400 0.0400
Isabella Bank    
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]    
Common equity Tier 1 capital to risk weighted assets, Actual, Amount $ 187,258 $ 172,589
Common equity Tier 1 capital to risk weighted assets, Actual, Ratio 0.1226 0.1153
Common equity Tier 1 capital to risk weighted assets, Minimum Capital Required Plus Capital Conservation Buffer, Amount $ 106,874 $ 104,783
Common equity Tier 1 capital to risk weighted assets, Minimum Capital Required Plus Capital Conservation Buffer, Ratio 7.00% 7.00%
Common equity Tier 1 capital to risk weighted assets, Minimum Capital Required To Be Considered Well Capitalized, Amount $ 99,240 $ 97,299
Common equity Tier 1 capital to risk weighted assets, Minimum Capital Required To Be Considered Well Capitalized, Ratio 0.0650 0.0650
Tier 1 capital to risk weighted assets, Actual, Amount $ 187,258 $ 172,589
Tier 1 capital to risk weighted assets, Actual, Ratio 0.1226 0.1153
Tier 1 capital to risk weighted assets, Minimum Capital Required Plus Capital Conservation Buffer, Amount $ 129,776 $ 127,237
Tier 1 capital to risk weighted assets, Minimum Capital Required Plus Capital Conservation Buffer, Ratio 0.0850 0.0850
Tier 1 capital to risk weighted assets, Minimum Capital Required To Be Considered Well Capitalized, Amount $ 122,142 $ 119,753
Tier 1 capital to risk weighted assets, Minimum Capital Required To Be Considered Well Capitalized, Ratio 0.0800 0.0800
Total capital to risk weighted assets, Actual, Amount $ 201,078 $ 185,997
Total capital to risk weighted assets, Actual, Ratio 0.1317 0.1243
Total capital to risk weighted assets, Minimum Capital Required Plus Capital Conservation Buffer, Amount $ 160,311 $ 157,175
Total capital to risk weighted assets, Minimum Capital Required Plus Capital Conservation Buffer, Ratio 0.1050 0.1050
Total capital to risk weighted assets, Minimum Capital Required To Be Considered Well Capitalized, Amount $ 152,677 $ 149,691
Total capital to risk weighted assets, Minimum Capital Required To Be Considered Well Capitalized, Ratio 0.1000 0.1000
Tier 1 capital to average assets, Actual, Amount $ 187,258 $ 172,589
Tier 1 capital to average assets, Actual, Ratio 0.0863 0.0836
Tier 1 capital to average assets, Minimum Capital Required Plus Capital Conservation Buffer, Amount $ 86,788 $ 82,602
Tier 1 capital to average assets, Minimum Capital Required Plus Capital Conservation Buffer, Ratio 0.0400 0.0400
Tier 1 capital to average assets, Minimum Capital Required To Be Considered Well Capitalized, Amount $ 108,486 $ 103,252
Tier 1 capital to average assets, Minimum Capital Required To Be Considered Well Capitalized, Ratio 0.0500 0.0500