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| 0000860413-18-000124-index.html | 2018-08-07 16:16:23 | |
| 0000860413-18-000124.txt | 2018-08-07 16:16:23 | |
 0000860413-18-000124-xbrl.zip | 410381 | 2018-08-07 16:16:23 |
| fibk-20180630.xml | 5116102 | 2018-08-07 16:16:23 |
| fibk-20180630.xsd | 78126 | 2018-08-07 16:16:23 |
| fibk-20180630x10q.htm | 3052948 | 2018-08-07 16:16:23 |
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| fibk-20180630xex32.htm | 4714 | 2018-08-07 16:16:23 |
| fibk-20180630_cal.xml | 189046 | 2018-08-07 16:16:23 |
| fibk-20180630_def.xml | 493707 | 2018-08-07 16:16:23 |
| fibk-20180630_lab.xml | 1134552 | 2018-08-07 16:16:23 |
| fibk-20180630_pre.xml | 688602 | 2018-08-07 16:16:23 |
| FilingSummary.xml | 45540 | 2018-08-07 16:16:23 |
| Financial_Report.xlsx | 126545 | 2018-08-07 16:16:23 |
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| report.css | 2767 | 2018-08-07 16:16:23 |
| Show.js | 1410 | 2018-08-07 16:16:23 |