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Subordinated Debt Securities (Details) (USD $) | 1 Months Ended | 12 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Apr. 29, 2004 | Dec. 16, 2003 | Dec. 31, 2012 | Dec. 31, 2011 | Dec. 31, 2010 | Aug. 30, 2012 | May 31, 2012 | Jul. 31, 2011
Class of Stock [Line Items] |  |  |  |  |  |  |  |
Common securities to the Company |  |  | $ 195,000 | $ 194,000 |  |  |  |
Subordinated Debt Securities (Textual) [Abstract] |  |  |  |  |  |  |  |
Aggregate principal amount of subordinated debt securities | 25,800,000 | 10,300,000 |  |  |  |  |  |
Redemption of debt securities |  |  |  |  |  |  | 12,900,000 | 10,300,000
Redemption of remaining debt securities |  |  |  |  |  | 12,900,000 |  |
Subordinated debt securities quarterly rate | LIBOR plus 3.80% per annum | LIBOR plus 4.10% per annum |  |  |  |  |  |
Debt securities interest rate | 3.80% | 4.10% |  | 4.30% | 4.40% |  |  |
Subordinated debt securities due |  |  | 2034 |  |  |  |  |
Amerisafe Capital Trust I [Member] |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |
Preferred securities to investors |  | 10,000,000 |  |  |  |  |  |
Common securities to the Company |  | 300,000 |  |  |  |  |  |
Amerisafe Capital Trust II [Member] |  |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |  |
Preferred securities to investors | 25,000,000 |  |  |  |  |  |  |
Common securities to the Company | $ 800,000 |  |  |  |  |  |  |

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