Related Party Transactions - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Related Party Transaction [Line Items]
Deposits from related parties	$ 184,108,000		$ 184,108,000		$ 316,141,000
Other income	2,465,000	$ 1,456,000	8,786,000	$ 7,491,000
Equity method investments	20,000,000		20,000,000
Amortized cost	1,673,079,000		1,673,079,000		1,658,779,000
Manufactured loan housing securities
Related Party Transaction [Line Items]
Mater loan purchase agreement, maximum capacity	250,000		$ 250,000
Master loan purchase agreement, term			5 years
Loans purchased	16,970,000	12,676,000	$ 43,776,000	19,125,000
Amortized cost	73,808,000		73,808,000		32,154,000
Preferred Stock
Related Party Transaction [Line Items]
Equity method investments	20,000,000		20,000,000
Equity security without readily determinable market value					10,000,000
Directors
Related Party Transaction [Line Items]
Operating lease expense	100,000	102,000	311,000	295,000
Directors | FBK Aviation, LLC | Aviation Time Sharing Agreements
Related Party Transaction [Line Items]
Other income	3,000	$ 15,000	46,000	$ 26,000
Unfunded Loan Commitment | Certain Executive Officers, Certain Management and Directors and Their Associates
Related Party Transaction [Line Items]
Unfunded commitments	$ 30,044,000		$ 30,044,000		$ 44,206,000