|
Document and Entity Information (USD $)
In Thousands, except Share data, unless otherwise specified |
12 Months Ended | ||
|---|---|---|---|
|
Dec. 31, 2013
|
Mar. 07, 2014
|
Jun. 30, 2013
|
|
| Document and Entity Information [Abstract] | |||
| Entity Registrant Name | ISABELLA BANK CORP | ||
| Entity Central Index Key | 0000842517 | ||
| Document Type | 10-K | ||
| Document Period End Date | Dec. 31, 2013 | ||
| Amendment Flag | false | ||
| Document Fiscal Year Focus | 2013 | ||
| Document Fiscal Period Focus | FY | ||
| Current Fiscal Year End Date | --12-31 | ||
| Entity Filer Category | Accelerated Filer | ||
| Entity Common Stock, Shares Outstanding | 7,725,471 | ||
| Entity Well-known Seasoned Issuer | No | ||
| Entity Voluntary Filers | No | ||
| Entity Current Reporting Status | Yes | ||
| Entity Public Float | $ 190,664 |