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| 0000860413-16-000051-index.html | 2016-08-05 13:10:33 | |
| 0000860413-16-000051.txt | 2016-08-05 13:10:33 | |
 0000860413-16-000051-xbrl.zip | 361489 | 2016-08-05 13:10:33 |
| fibk-20160630.xml | 4736449 | 2016-08-05 13:10:33 |
| fibk-20160630.xsd | 56634 | 2016-08-05 13:10:33 |
| fibk-20160630x10q.htm | 2666418 | 2016-08-05 13:10:33 |
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| fibk-20160630xex32.htm | 4968 | 2016-08-05 13:10:33 |
| fibk-20160630_cal.xml | 150041 | 2016-08-05 13:10:33 |
| fibk-20160630_def.xml | 483569 | 2016-08-05 13:10:33 |
| fibk-20160630_lab.xml | 926656 | 2016-08-05 13:10:33 |
| fibk-20160630_pre.xml | 578346 | 2016-08-05 13:10:33 |
| FilingSummary.xml | 35320 | 2016-08-05 13:10:33 |
| Financial_Report.xlsx | 109546 | 2016-08-05 13:10:33 |
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| report.css | 2767 | 2016-08-05 13:10:33 |
| Show.js | 1410 | 2016-08-05 13:10:33 |