Parent Directory| Name | Size | Last Modified |
|---|---|---|
 0000860413-25-000006-index-headers.html | 2025-01-29 16:28:23 | |
| 0000860413-25-000006-index.html | 2025-01-29 16:28:23 | |
| 0000860413-25-000006.txt | 2025-01-29 16:28:23 | |
 0000860413-25-000006-xbrl.zip | 61956 | 2025-01-29 16:28:23 |
| dec2024ip.htm | 34124 | 2025-01-29 16:28:23 |
 dec2024ip001.jpg | 139106 | 2025-01-29 16:28:23 |
 dec2024ip002.jpg | 266790 | 2025-01-29 16:28:23 |
 dec2024ip003.jpg | 94118 | 2025-01-29 16:28:23 |
 dec2024ip004.jpg | 214748 | 2025-01-29 16:28:23 |
 dec2024ip005.jpg | 91823 | 2025-01-29 16:28:23 |
 dec2024ip006.jpg | 84552 | 2025-01-29 16:28:23 |
 dec2024ip007.jpg | 92677 | 2025-01-29 16:28:23 |
 dec2024ip008.jpg | 104600 | 2025-01-29 16:28:23 |
 dec2024ip009.jpg | 96414 | 2025-01-29 16:28:23 |
 dec2024ip010.jpg | 119637 | 2025-01-29 16:28:23 |
 dec2024ip011.jpg | 101382 | 2025-01-29 16:28:23 |
 dec2024ip012.jpg | 59256 | 2025-01-29 16:28:23 |
 dec2024ip013.jpg | 78170 | 2025-01-29 16:28:23 |
 dec2024ip014.jpg | 80119 | 2025-01-29 16:28:23 |
 dec2024ip015.jpg | 104056 | 2025-01-29 16:28:23 |
 dec2024ip016.jpg | 279263 | 2025-01-29 16:28:23 |
 dec2024ip017.jpg | 112591 | 2025-01-29 16:28:23 |
 dec2024ip018.jpg | 105583 | 2025-01-29 16:28:23 |
| fibk-20241231x8kpr.htm | 964552 | 2025-01-29 16:28:23 |
| fibk-20250129.htm | 32929 | 2025-01-29 16:28:23 |
| fibk-20250129.xsd | 1773 | 2025-01-29 16:28:23 |
| fibk-20250129_htm.xml | 2723 | 2025-01-29 16:28:23 |
| fibk-20250129_lab.xml | 21885 | 2025-01-29 16:28:23 |
| fibk-20250129_pre.xml | 12502 | 2025-01-29 16:28:23 |
 fibslogo2linea04a.jpg | 165531 | 2025-01-29 16:28:23 |
| FilingSummary.xml | 1618 | 2025-01-29 16:28:23 |
| Financial_Report.xlsx | 5693 | 2025-01-29 16:28:23 |
| MetaLinks.json | 16850 | 2025-01-29 16:28:23 |
| R1.htm | 38092 | 2025-01-29 16:28:23 |
| report.css | 2767 | 2025-01-29 16:28:23 |
| Show.js | 1085 | 2025-01-29 16:28:23 |