v3.25.3

Cover	Nov. 14, 2025
Cover [Abstract]
Document Type	8-K
Amendment Flag	false
Document Period End Date	Nov. 14, 2025
Entity File Number	001-37875
Entity Registrant Name	FB FINANCIAL CORPORATION
Entity Central Index Key	0001649749
Entity Tax Identification Number	62-1216058
Entity Incorporation, State or Country Code	TN
Entity Address, Address Line One	1221 Broadway
Entity Address, Address Line Two	Suit 1300
Entity Address, City or Town	Nashville
Entity Address, State or Province	TN
Entity Address, Postal Zip Code	37203
City Area Code	615
Local Phone Number	564-1212
Written Communications	false
Soliciting Material	false
Pre-commencement Tender Offer	false
Pre-commencement Issuer Tender Offer	false
Title of 12(b) Security	Common Stock, $1.00 par value
Trading Symbol	FBK
Security Exchange Name	NYSE
Entity Emerging Growth Company	false

Boolean flag that is true when the XBRL content amends previously-filed or accepted submission.

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No definition available.

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- Definition

Area code of city

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No definition available.

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- Definition

Cover page.

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No definition available.

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- Definition

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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No definition available.

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- Definition

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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No definition available.

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- Definition

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

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No definition available.

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- Definition

Address Line 2 such as Street or Suite number

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No definition available.

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Name of the City or Town

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No definition available.

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- Definition

Code for the postal or zip code

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No definition available.

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- Definition

Name of the state or province.

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No definition available.

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
-Number 240
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- Definition

Indicate if registrant meets the emerging growth company criteria.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition

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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No definition available.

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- Definition

Two-character EDGAR code representing the state or country of incorporation.

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No definition available.

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- Definition

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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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
-Number 240
-Section 12
-Subsection b-2

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- Definition

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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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
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- Definition

Local phone number for entity.

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No definition available.

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Namespace Prefix:	dei_
Data Type:	xbrli:normalizedStringItemType
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- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Exchange Act
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-Subsection 4c

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- Definition

Boolean flag that is true when the Form 8-K filing is intended to satisfy the filing obligation of the registrant as pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Exchange Act
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- Definition

Title of a 12(b) registered security.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Name of the Exchange on which a security is registered.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Exchange Act
-Number 240
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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Exchange Act
-Number 240
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-Subsection 12

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- Definition

Trading symbol of an instrument as listed on an exchange.

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No definition available.

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- Definition

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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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Securities Act
-Number 230
-Section 425

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FB Financial Corp 8-K