FinObservatory

SEC filings / CIK 860413

FIRST INTERSTATE BANCSYSTEM INC

State commercial banks, MT. 15 10-K filer-years in this dataset, the most recent for FY2025, filed Feb 26, 2026. Every figure below is as filed by the company and untouched: FinObservatory has not restated, rescaled or corrected anything, and a blank is a fact the filing does not tag, not a zero.

This is the SEC holding company, identified by its Central Index Key. It is not the insured bank subsidiary that appears in /banks and /deposits, which are FDIC call-report entities on a different consolidation. Nothing here should be compared line for line with those.

Held-to-maturity gap against reported equity

The fair value of the held-to-maturity book minus its carrying amount, divided by the stockholders’ equity the same filing reports. Years marked n/a are years in which the filing does not tag one of the three.

-15-10-505FY2011: HTM fair value less carrying amount, +1.2% of reported stockholders’ equityFY2012: HTM fair value less carrying amount, +1.4% of reported stockholders’ equityFY2013: HTM fair value less carrying amount, +0.3% of reported stockholders’ equityFY2014: HTM fair value less carrying amount, +1.0% of reported stockholders’ equityFY2015: HTM fair value less carrying amount, +0.7% of reported stockholders’ equityFY2016: HTM fair value less carrying amount, +0.1% of reported stockholders’ equityFY2017: HTM fair value less carrying amount, -0.1% of reported stockholders’ equityFY2018: HTM fair value less carrying amount, -0.4% of reported stockholders’ equityFY2019: HTM fair value less carrying amount, +0.1% of reported stockholders’ equityFY2020: HTM fair value less carrying amount, +0.2% of reported stockholders’ equityFY2021: HTM fair value less carrying amount, -1.0% of reported stockholders’ equityFY2022: HTM fair value less carrying amount, -13.0% of reported stockholders’ equityFY2023: HTM fair value less carrying amount, -10.3% of reported stockholders’ equityFY2024: HTM fair value less carrying amount, -10.0% of reported stockholders’ equityFY2025 (partial): HTM fair value less carrying amount, -6.0% of reported stockholders’ equity111213141516171819202122232425Fiscal year of the 10-K% of reported stockholders’ equity

The gap is computable for 15 of this company’s 15 filings.

Source: SEC Financial Statement Data Sets, US Securities and Exchange Commission, Division of Economic and Risk Analysis. Facts as filed: uncleaned, unrestated, not audited by FinObservatory. Selection: consolidated USD balance-sheet instants at each filing's own period end, from this company's 10-K submissions with prevrpt = 0. Methodology

Filing history, as filed

FYFiledAssetsDepositsEquityAOCIHTM carryingHTM fair valueGap, % of equityCustom facts
2025pFeb 26, 2026$26.64bn$22.09bn$3.45bn-$178.1m$2.34bn$2.14bn-6.0%9.0%
2024Feb 28, 2025$29.14bn$23.02bn$3.30bn-$321.9m$2.69bn$2.36bn-10.0%11.2%
2023Feb 29, 2024$30.67bn$23.32bn$3.23bn-$356.5m$3.21bn$2.87bn-10.3%13.5%
2022Feb 24, 2023$32.29bn$25.07bn$3.07bn-$477.1m$3.45bn$3.05bn-13.0%12.6%
2021Feb 25, 2022$19.67bn$16.27bn$1.99bn-$11.0m$1.69bn$1.67bn-1.0%10.5%
2020Mar 1, 2021$17.65bn$14.22bn$1.96bn$56.6m$51.6m$55.0m+0.2%10.9%
2019Feb 27, 2020$14.64bn$11.66bn$2.01bn$11.0m$92.3m$94.5m+0.1%14.0%
2018Feb 27, 2019$13.30bn$10.68bn$1.69bn-$24.6m$406.8m$400.7m-0.4%13.2%
2017Feb 28, 2018$12.21bn$9.93bn$1.43bn-$12.0m$484.5m$483.3m-0.1%12.3%
2016Mar 2, 2017$9.06bn$7.38bn$982.6m-$8.1m$512.8m$513.3m+0.1%3.8%
2015Mar 1, 2016$8.73bn$7.09bn$950.5m$406k$600.7m$607.5m+0.7%5.3%
2014Mar 2, 2015$8.61bn$7.01bn$908.9m-$2.5m$575.2m$584.5m+1.0%5.2%
2013Feb 28, 2014$7.56bn$6.13bn$801.6m-$16.0m$203.8m$205.9m+0.3%5.9%
2012Mar 1, 2013$7.72bn$6.24bn$751.2m$16.0m$208.2m$218.9m+1.4%7.5%
2011Feb 28, 2012$7.33bn$5.83bn$771.0m$19.0m$152.8m$161.9m+1.2%8.0%

ext marks a carrying amount tagged with a company-invented element. p marks FY2025, which the dataset’s filing window (closing Mar 31, 2026) leaves incomplete across filers. “Custom facts” is the share of that filing’s consolidated facts carrying a company-invented tag, in any unit.

Source: SEC Financial Statement Data Sets, US Securities and Exchange Commission, Division of Economic and Risk Analysis. Facts as filed: uncleaned, unrestated, not audited by FinObservatory. Selection: this company's 10-K submissions with prevrpt = 0, one per fiscal year by latest filed date; consolidated USD instants at each filing's period end. Dollar columns are raw US dollars. Methodology

What this page cannot tell you

  • A blank in the held-to-maturity columns means the filing does not tag that fact on the consolidated face. It does not mean the company holds no held-to-maturity securities, and this dataset cannot distinguish the two.
  • A held-to-maturity gap is not a realised loss. Held to maturity, the securities pay par. The gap measures how far the reported equity sits from a mark-to-market equity, which becomes a solvency question only if the book must be sold.
  • AOCI is not the held-to-maturity mark. It bundles available-for-sale marks, hedge marks, pension and translation, net of tax. Do not add the two columns.
  • Every value is as filed. A scale error, sign error or mis-tag by the company is reproduced here exactly as the company made it.

Pages exist for the 650 bank and thrift holding companies with at least one 10-K from FY2015 onward, out of 900 with a 10-K anywhere in the dataset.