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Share-based Compensation Arrangement By Share-based Payment Award, Fair Value Assumptions, Expected Volatility, Number Of Comparable Companies

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Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Face amount or stated value per share of common stock.

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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Amount of cost to be recognized for option under share-based payment arrangement.

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Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.

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Number of shares issued for nonredeemable preferred shares and preferred shares redeemable solely at option of issuer. Includes, but is not limited to, preferred shares issued, repurchased, and held as treasury shares. Excludes preferred shares classified as debt.

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Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Stockholders' Equity - Narrative (Details) $ / shares in Units, $ in Thousands	1 Months Ended		3 Months Ended		6 Months Ended
	Apr. 30, 2025 shares	Mar. 31, 2024 shares	Jun. 30, 2025 USD ($) $ / shares shares	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($) company $ / shares shares	Jun. 30, 2024 USD ($)	Dec. 31, 2024 $ / shares shares	Dec. 31, 2021 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred stock, shares authorized (in shares)			10,000,000		10,000,000		10,000,000
Preferred stock, par value (in dollars per share) \| $ / shares			$ 0.0001		$ 0.0001		$ 0.0001
Preferred stock, shares outstanding (in shares)			0		0		0
Preferred stock, shares issued (in shares)			0		0		0
Common stock, shares authorized (in shares)			50,000,000		50,000,000		50,000,000
Common stock, par value (in dollars per share) \| $ / shares			$ 0.0001		$ 0.0001		$ 0.0001
Balance, beginning of period (in shares)			27,834,525		27,834,525		27,709,679
Common stock, shares issued (in shares)			27,834,525		27,834,525		27,709,679
Option awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award contractual term					10 years
Option awards \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility, number of comparable companies \| company					25
Option awards \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility, number of comparable companies \| company					30
Option awards \| First Anniversaries
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage					25.00%
Option awards \| Fourth Anniversaries
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage					25.00%
Option awards \| Second Anniversaries
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage					25.00%
Option awards \| Third Anniversaries
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage					25.00%
Performance-based restricted stock \| April 2024
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost related to non-vested stock options granted \| $			$ 1,743		$ 1,743
Awards expected to issue (in shares)			84,150		84,150
Performance-based restricted stock \| May 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost related to non-vested stock options granted \| $			$ 545		$ 545
Awards expected to issue (in shares)			77,873		77,873
FirstSun Capital Bancorp 2017 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate shares of common stock (in shares)			1,977,292		1,977,292
Intrinsic value of the stock options \| $			$ 10,319	$ 17,439	$ 10,319	$ 17,439
FirstSun Capital Bancorp 2021 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate shares of common stock (in shares)								2,476,571
Restricted stock grant activity, net of forfeitures (in shares)		11,739	40,351		44,627
Total unrecognized compensation cost related to non-vested stock options granted \| $			$ 1,170		$ 1,170
Forfeiture of restricted stock grants (in shares)			2,558		2,558
FirstSun Capital Bancorp 2021 Equity Incentive Plan \| April 2025
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost related to non-vested stock options granted \| $			$ 4,703		$ 4,703
FirstSun Capital Bancorp 2021 Equity Incentive Plan \| Restricted Stock - Service Condition
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock grant activity, net of forfeitures (in shares)	71,012
FirstSun Capital Bancorp 2021 Equity Incentive Plan \| Restricted Stock - Market Condition and Service Condition
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock grant activity, net of forfeitures (in shares)	71,001
FirstSun Capital Bancorp 2017 And 2021 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment arrangement, compensation cost \| $			1,056	772	1,692	1,264
Pioneer's Option Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of the stock options \| $			$ 868	$ 1,243	$ 868	$ 1,243