Parent Directory| Name | Size | Last Modified |
|---|---|---|
 0000860413-25-000147-index-headers.html | 2025-09-09 16:48:27 | |
| 0000860413-25-000147-index.html | 2025-09-09 16:48:27 | |
| 0000860413-25-000147.txt | 2025-09-09 16:48:27 | |
 0000860413-25-000147-xbrl.zip | 10775 | 2025-09-09 16:48:27 |
| fibk-20250903.htm | 32239 | 2025-09-09 16:48:27 |
| fibk-20250903.xsd | 1773 | 2025-09-09 16:48:27 |
| fibk-20250903_htm.xml | 2723 | 2025-09-09 16:48:27 |
| fibk-20250903_lab.xml | 21885 | 2025-09-09 16:48:27 |
| fibk-20250903_pre.xml | 12502 | 2025-09-09 16:48:27 |
| FilingSummary.xml | 1618 | 2025-09-09 16:48:27 |
| MetaLinks.json | 16849 | 2025-09-09 16:48:27 |
| R1.htm | 38077 | 2025-09-09 16:48:27 |
| report.css | 2766 | 2025-09-09 16:48:27 |
| Show.js | 1084 | 2025-09-09 16:48:27 |