Parent Directory| Name | Size | Last Modified |
|---|---|---|
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| 0000860413-23-000190-index.html | 2023-11-30 15:45:02 | |
| 0000860413-23-000190.txt | 2023-11-30 15:45:02 | |
 0000860413-23-000190-xbrl.zip | 11615 | 2023-11-30 15:45:02 |
| fibk-20231128.htm | 34742 | 2023-11-30 15:45:02 |
| fibk-20231128.xsd | 1892 | 2023-11-30 15:45:02 |
| fibk-20231128_htm.xml | 2723 | 2023-11-30 15:45:02 |
| fibk-20231128_lab.xml | 24139 | 2023-11-30 15:45:02 |
| fibk-20231128_pre.xml | 12502 | 2023-11-30 15:45:02 |
| fibk-ex161_letterfromrsmus.htm | 3262 | 2023-11-30 15:45:02 |
| FilingSummary.xml | 1618 | 2023-11-30 15:45:02 |
| Financial_Report.xlsx | 5691 | 2023-11-30 15:45:02 |
| MetaLinks.json | 16850 | 2023-11-30 15:45:02 |
| R1.htm | 38092 | 2023-11-30 15:45:02 |
| report.css | 2767 | 2023-11-30 15:45:02 |
 rsm_usxllp.jpg | 4699 | 2023-11-30 15:45:02 |
| Show.js | 1085 | 2023-11-30 15:45:02 |