Cover
Cover | Aug. 24, 2023 |
Cover [Abstract] | |
Document Type | 8-K |
Document Period End Date | Aug. 24, 2023 |
Entity Registrant Name | FIRST INTERSTATE BANCSYSTEM, INC. |
Entity Incorporation, State or Country Code | DE |
Entity File Number | 001-34653 |
Entity Tax Identification Number | 81-0331430 |
Entity Address, Address Line One | 401 North 31st Street |
Entity Address, City or Town | Billings, |
Entity Address, State or Province | MT |
Entity Address, Postal Zip Code | 59101 |
City Area Code | (406) |
Local Phone Number | 255-5311 |
Written Communications | false |
Soliciting Material | false |
Pre-commencement Tender Offer | false |
Pre-commencement Issuer Tender Offer | false |
Title of 12(b) Security | Class A common stock, $0.00001 par value |
Trading Symbol | FIBK |
Security Exchange Name | NASDAQ |
Amendment Flag | false |
Entity Central Index Key | 0000860413 |
Entity Emerging Growth Company | false |