Parent Directory| Name | Size | Last Modified |
|---|---|---|
 0000860413-25-000119-index-headers.html | 2025-08-15 13:31:23 | |
| 0000860413-25-000119-index.html | 2025-08-15 13:31:23 | |
| 0000860413-25-000119.txt | 2025-08-15 13:31:23 | |
 0000860413-25-000119-xbrl.zip | 10026 | 2025-08-15 13:31:23 |
| fibk-20250813.htm | 30393 | 2025-08-15 13:31:23 |
| fibk-20250813.xsd | 1773 | 2025-08-15 13:31:23 |
| fibk-20250813_htm.xml | 2723 | 2025-08-15 13:31:23 |
| fibk-20250813_lab.xml | 21885 | 2025-08-15 13:31:23 |
| fibk-20250813_pre.xml | 12502 | 2025-08-15 13:31:23 |
| FilingSummary.xml | 1618 | 2025-08-15 13:31:23 |
| MetaLinks.json | 16849 | 2025-08-15 13:31:23 |
| R1.htm | 38076 | 2025-08-15 13:31:23 |
| report.css | 2766 | 2025-08-15 13:31:23 |
| Show.js | 1084 | 2025-08-15 13:31:23 |