v3.25.3

Cover	Dec. 03, 2025
Cover [Abstract]
Document Type	8-K/A
Document Period End Date	Dec. 03, 2025
Entity Registrant Name	FIRSTSUN CAPITAL BANCORP
Entity Incorporation, State or Country Code	DE
Entity File Number	001-42175
Entity Tax Identification Number	81-4552413
Entity Address, Address Line One	1400 16th Street
Entity Address, Address Line Two	Suite 250
Entity Address, City or Town	Denver
Entity Address, State or Province	CO
Entity Address, Postal Zip Code	80202
City Area Code	303
Local Phone Number	831-6704
Written Communications	true
Soliciting Material	false
Pre-commencement Tender Offer	false
Pre-commencement Issuer Tender Offer	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Central Index Key	0001709442
Amendment Flag	true
Trading Symbol	FSUN
Security Exchange Name	NASDAQ
Title of 12(b) Security	Common Stock, $.0001 Par Value
Amendment Description	This Current Report on Form 8-K/A (the “Amendment”) of FirstSun Capital Bancorp (the “Company”) amends the Current Report on Form 8-K filed by the Company on December 4, 2025 (the “Original Report”). The sole purpose of the Amendment is the insertion of the correct date for the signature in the Original Report. No other revisions have been made to the Original Report.

Description of changes contained within amended document.

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For the EDGAR submission types of Form 8-K: the date of the report, the date of the earliest event reported; for the EDGAR submission types of Form N-1A: the filing date; for all other submission types: the end of the reporting or transition period. The format of the date is YYYY-MM-DD.

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The type of document being provided (such as 10-K, 10-Q, 485BPOS, etc). The document type is limited to the same value as the supporting SEC submission type, or the word 'Other'.

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Address Line 1 such as Attn, Building Name, Street Name

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A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.

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Commission file number. The field allows up to 17 characters. The prefix may contain 1-3 digits, the sequence number may contain 1-8 digits, the optional suffix may contain 1-4 characters, and the fields are separated with a hyphen.

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The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.

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The Tax Identification Number (TIN), also known as an Employer Identification Number (EIN), is a unique 9-digit value assigned by the IRS.

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Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as soliciting material pursuant to Rule 14a-12 under the Exchange Act.

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Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as written communications pursuant to Rule 425 under the Securities Act.

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FIRSTSUN CAPITAL BANCORP 8-K/A