Parent Directory| Name | Size | Last Modified |
|---|---|---|
 0000860413-13-000009-index-headers.html | 2013-04-30 17:44:41 | |
| 0000860413-13-000009-index.html | 2013-04-30 17:44:41 | |
| 0000860413-13-000009.txt | 2013-04-30 17:44:41 | |
 0000860413-13-000009-xbrl.zip | 279622 | 2013-04-30 17:44:41 |
| fibk-20130331.xml | 3312378 | 2013-04-30 17:44:41 |
| fibk-20130331.xsd | 49070 | 2013-04-30 17:44:41 |
| fibk-20130331x10q.htm | 1953208 | 2013-04-30 17:44:41 |
| fibk-20130331xex1010.htm | 9458 | 2013-04-30 17:44:41 |
| fibk-20130331xex311.htm | 11983 | 2013-04-30 17:44:41 |
| fibk-20130331xex312.htm | 12346 | 2013-04-30 17:44:41 |
| fibk-20130331xex32.htm | 4810 | 2013-04-30 17:44:41 |
| fibk-20130331_cal.xml | 141899 | 2013-04-30 17:44:41 |
| fibk-20130331_def.xml | 366203 | 2013-04-30 17:44:41 |
| fibk-20130331_lab.xml | 769164 | 2013-04-30 17:44:41 |
| fibk-20130331_pre.xml | 452693 | 2013-04-30 17:44:41 |
| FilingSummary.xml | 26047 | 2013-04-30 17:44:41 |
| Financial_Report.xls | 2608372 | 2013-04-30 17:44:41 |
| R1.htm | 25000 | 2013-04-30 17:44:41 |
| R10.htm | 201925 | 2013-04-30 17:44:41 |
| R11.htm | 474111 | 2013-04-30 17:44:41 |
| R12.htm | 118227 | 2013-04-30 17:44:41 |
| R13.htm | 24944 | 2013-04-30 17:44:41 |
| R14.htm | 17759 | 2013-04-30 17:44:41 |
| R15.htm | 27080 | 2013-04-30 17:44:41 |
| R16.htm | 84743 | 2013-04-30 17:44:41 |
| R17.htm | 9877 | 2013-04-30 17:44:41 |
| R18.htm | 8076 | 2013-04-30 17:44:41 |
| R19.htm | 10701 | 2013-04-30 17:44:41 |
| R2.htm | 171061 | 2013-04-30 17:44:41 |
| R20.htm | 51883 | 2013-04-30 17:44:41 |
| R21.htm | 197248 | 2013-04-30 17:44:41 |
| R22.htm | 14032 | 2013-04-30 17:44:41 |
| R23.htm | 6243 | 2013-04-30 17:44:41 |
| R24.htm | 203378 | 2013-04-30 17:44:41 |
| R25.htm | 471801 | 2013-04-30 17:44:41 |
| R26.htm | 115676 | 2013-04-30 17:44:41 |
| R27.htm | 18095 | 2013-04-30 17:44:41 |
| R28.htm | 21931 | 2013-04-30 17:44:41 |
| R29.htm | 80341 | 2013-04-30 17:44:41 |
| R3.htm | 21883 | 2013-04-30 17:44:41 |
| R30.htm | 51739 | 2013-04-30 17:44:41 |
| R31.htm | 184594 | 2013-04-30 17:44:41 |
| R32.htm | 64326 | 2013-04-30 17:44:41 |
| R33.htm | 9336 | 2013-04-30 17:44:41 |
| R34.htm | 71930 | 2013-04-30 17:44:41 |
| R35.htm | 82424 | 2013-04-30 17:44:41 |
| R36.htm | 31124 | 2013-04-30 17:44:41 |
| R37.htm | 97792 | 2013-04-30 17:44:41 |
| R38.htm | 71675 | 2013-04-30 17:44:41 |
| R39.htm | 49758 | 2013-04-30 17:44:41 |
| R4.htm | 151396 | 2013-04-30 17:44:41 |
| R40.htm | 87258 | 2013-04-30 17:44:41 |
| R41.htm | 71186 | 2013-04-30 17:44:41 |
| R42.htm | 16889 | 2013-04-30 17:44:41 |
| R43.htm | 10285 | 2013-04-30 17:44:41 |
| R44.htm | 53709 | 2013-04-30 17:44:41 |
| R45.htm | 74082 | 2013-04-30 17:44:41 |
| R46.htm | 7214 | 2013-04-30 17:44:41 |
| R47.htm | 8688 | 2013-04-30 17:44:41 |
| R48.htm | 12429 | 2013-04-30 17:44:41 |
| R49.htm | 59037 | 2013-04-30 17:44:41 |
| R5.htm | 45789 | 2013-04-30 17:44:41 |
| R50.htm | 15919 | 2013-04-30 17:44:41 |
| R51.htm | 73376 | 2013-04-30 17:44:41 |
| R52.htm | 84405 | 2013-04-30 17:44:41 |
| R6.htm | 68427 | 2013-04-30 17:44:41 |
| R7.htm | 32093 | 2013-04-30 17:44:41 |
| R8.htm | 190780 | 2013-04-30 17:44:41 |
| R9.htm | 9468 | 2013-04-30 17:44:41 |
| report.css | 2721 | 2013-04-30 17:44:41 |
| Show.js | 6423 | 2013-04-30 17:44:41 |