Parent Directory| Name | Size | Last Modified |
|---|---|---|
 0000860413-23-000202-index-headers.html | 2023-12-14 17:24:42 | |
| 0000860413-23-000202-index.html | 2023-12-14 17:24:42 | |
| 0000860413-23-000202.txt | 2023-12-14 17:24:42 | |
 0000860413-23-000202-xbrl.zip | 16386 | 2023-12-14 17:24:42 |
| fibk-20231214.htm | 33151 | 2023-12-14 17:24:42 |
| fibk-20231214.xsd | 1892 | 2023-12-14 17:24:42 |
| fibk-20231214xex101_scottt.htm | 38614 | 2023-12-14 17:24:42 |
| fibk-20231214_htm.xml | 2723 | 2023-12-14 17:24:42 |
| fibk-20231214_lab.xml | 24139 | 2023-12-14 17:24:42 |
| fibk-20231214_pre.xml | 12502 | 2023-12-14 17:24:42 |
| FilingSummary.xml | 1618 | 2023-12-14 17:24:42 |
| Financial_Report.xlsx | 5690 | 2023-12-14 17:24:42 |
| MetaLinks.json | 16850 | 2023-12-14 17:24:42 |
| R1.htm | 38092 | 2023-12-14 17:24:42 |
| report.css | 2767 | 2023-12-14 17:24:42 |
| Show.js | 1084 | 2023-12-14 17:24:42 |