v2.4.0.6

Shareholder Equity - Additional Information (Detail) | 3 Months Ended
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Sep. 30, 2012
Subsidiary or Equity Method Investee [Line Items] |
Remaining percentage of interest of subsidiary, AMT warranty | 20.00%

X
- Definition Subsidiary or Equity Method Investee Percentage Ownership Acquired + References No definition available. + Details
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Namespace Prefix: | afsi_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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- Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration