| **Contingent Liabilities**                              | 3 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
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| **Commitments and Contingencies Disclosure [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| Contingent Liabilities                                  | CONTINGENT LIABILITIESOn April 16, 2013, First Merchants was named in a class action lawsuit in Delaware County Circuit Court challenging First Merchant's checking account practices associated with the assessment of overdraft fees.  The plaintiff seeks damages and other relief, including restitution and injunctive relief.  First Merchants believes it has meritorious defenses to the claims brought by the plaintiff.  At this phase of the litigation, it is not possible for management of First Merchants to determine the probability of a material adverse outcome or reasonably estimate the amount of any loss.  No class has yet been certified and discovery is still ongoing. |

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| - Definition
The entire disclosure for legal proceedings, legal contingencies, litigation, regulatory and environmental matters and other contingencies.
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No definition available.
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