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| 0001193125-11-303389.txt | 2011-11-09 08:29:52 | |
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| d235579d10q.htm | 1610906 | 2011-11-09 08:29:52 |
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| fibk-20110930.xsd | 14899 | 2011-11-09 08:29:52 |
| fibk-20110930_cal.xml | 62090 | 2011-11-09 08:29:52 |
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| FilingSummary.xml | 11122 | 2011-11-09 08:29:52 |
| Financial_Report.xls | 1016057 | 2011-11-09 08:29:52 |
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| R2.htm | 151608 | 2011-11-09 08:29:52 |
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