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| 0000860413-16-000061-index.html | 2016-11-07 18:42:30 | |
| 0000860413-16-000061.txt | 2016-11-07 18:42:30 | |
 0000860413-16-000061-xbrl.zip | 386208 | 2016-11-07 18:42:30 |
| fibk-20160930.xml | 5033824 | 2016-11-07 18:42:30 |
| fibk-20160930.xsd | 64039 | 2016-11-07 18:42:30 |
| fibk-20160930x10q.htm | 2754449 | 2016-11-07 18:42:30 |
| fibk-20160930xex311.htm | 12246 | 2016-11-07 18:42:30 |
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| fibk-20160930xex32.htm | 4750 | 2016-11-07 18:42:30 |
| fibk-20160930_cal.xml | 155521 | 2016-11-07 18:42:30 |
| fibk-20160930_def.xml | 493540 | 2016-11-07 18:42:30 |
| fibk-20160930_lab.xml | 1000878 | 2016-11-07 18:42:30 |
| fibk-20160930_pre.xml | 609171 | 2016-11-07 18:42:30 |
| FilingSummary.xml | 38303 | 2016-11-07 18:42:30 |
| Financial_Report.xlsx | 119402 | 2016-11-07 18:42:30 |
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| report.css | 2767 | 2016-11-07 18:42:30 |
| Show.js | 1410 | 2016-11-07 18:42:30 |