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Capital Stock | 6 Months Ended
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Jun. 30, 2025
Equity [Abstract] |
Capital Stock | The Company’s common stock is traded on the NASDAQ stock market under the symbol “FIBK.” As of June 30, 2025, the Company is authorized to issue an aggregate of 150,100,000 shares of capital stock, of which 150,000,000 shares are designated as common stock, and 100,000 are designated as preferred stock. Our common stock is uncertificated and has one vote per share. The Company had 104,874,177 shares and 104,585,964 shares of common stock outstanding as of June 30, 2025 and December 31, 2024, respectively, and no shares of preferred stock outstanding as of June 30, 2025 and December 31, 2024. During the six months ended June 30, 2025, the Company issued 35,352 restricted stock units to directors for their annual service on the Company's board of directors. The aggregate value of the restricted stock units issued to directors of $1.0 million is amortized into stock-based compensation expense in the accompanying consolidated statements of changes in stockholders’ equity over a one-year service-based period. As of June 30, 2025, the Company does not have a stock repurchase program in place. Stock repurchases during the six months ended June 30, 2025 and 2024, were redemptions of vested restricted shares tendered in lieu of cash for payment of income tax withholding amounts by participants in the Company’s equity compensation plans.

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