XML 22 R13.htm IDEA: XBRL DOCUMENT
v3.23.1

Loans Held for Sale | 3 Months Ended
--- | ---
Mar. 31, 2023
Loans Held for Sale [Abstract] |
Loans Held for Sale | The following table presents loans held for sale by portfolio segment for the dates indicated:
| March 31, 2023 |  | December 31, 2022
Loans held for sale: |  |  |
Agricultural 1 | $ | 62.9 |  |  | $ | 62.5 |
Commercial construction, at lower of cost or market | 6.4 |  |  | 10.5 |
Land acquisition and development, at lower of cost or market | 3.1 |  |  | — |
Residential mortgage, at fair value | 8.5 |  |  | 6.9 |
Total loans held for sale | $ | 80.9 |  |  | $ | 79.9 |
1 The Company holds $55.4 million of agricultural loans at lower of cost or market and $7.5 million of agricultural loans on accrual status at fair value with an unpaid principal balance of $7.5 million, of which $5.6 million is 90 days or more past due. The table below presents the non-residential mortgage loans held for sale activity for the quarter ended March 31, 2023:
| Agricultural |  | Commercial Construction |  | Land Acquisition and Development
Beginning balance | $ | 62.5 |  |  | $ | 10.5 |  |  | $ | — |
Repayments and discounted pay-offs | (1.8) |  |  | — |  |  | — |
Loans held for investment transferred to loans held for sale | — |  |  | — |  |  | 3.1 |
Increase (decrease) in estimated fair value of the loans 1 | 2.2 |  |  | (4.1) |  |  | — |
Ending balance | $ | 62.9 |  |  | $ | 6.4 |  |  | $ | 3.1 |
1 For the three months ended March 31, 2023, the Company recorded a gain of $2.2 million and a loss of $4.1 million in other income within the consolidated statements of income (loss) related to fair value changes. As of March 31, 2023, loans held for sale included nonaccrual loans of $37.5 million, of which $28.0 million were agricultural loans, $6.4 million was a commercial construction loan, and $3.1 million was a land acquisition and development construction loan. As of December 31, 2022, loans held for sale included nonaccrual loans of $39.8 million, of which $29.3 million were agricultural loans and $10.5 million was a commercial construction loan.

X
- Definition Loans Held For Sale [Text Block] + References No definition available. + Details
Name: | fibk_LoansHeldForSaleTextBlock
Namespace Prefix: | fibk_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Loans Held for Sale [Abstract] + References No definition available. + Details
Name: | fibk_LoansHeldforSaleAbstract
Namespace Prefix: | fibk_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration