Borrowings - Additional Information (Detail) - USD ($)							6 Months Ended	12 Months Ended
	Oct. 12, 2023	Sep. 26, 2023	Sep. 15, 2023	Feb. 10, 2023	Feb. 11, 2022	Jun. 29, 2020	Jun. 30, 2024	Dec. 31, 2023	Jul. 23, 2020
Debt Instrument [Line Items]
Total Federal Home Loan Bank advances							$ 250,306,000	$ 100,000,000
Line of credit facility maximum borrowing capacity				$ 25,000,000
Debt Instrument, Maturity Date				Feb. 10, 2024	Feb. 11, 2023
Debt instrument term							5 years
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage				20.00%	0.20%
Debt instrument floating daily, floor Interest Rate				3.25%	3.25%		3.50%
Trust Preferred Securities [Member] | FCB Capital Trust II [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date							Apr. 15, 2035
Subordinated debenture basis spread on variable rate							2.00%
Preferred securities liquidation spread percent	2.00%
Trust Preferred Securities [Member] | FCB Capital Trust II [Member] | Tenor Spread Adjustment [Member]
Debt Instrument [Line Items]
Preferred securities liquidation spread percent	0.26%
Trust Preferred Securities [Member] | FCB Capital Trust III [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date							Jun. 15, 2037
Subordinated debenture basis spread on variable rate							1.89%
Preferred securities liquidation spread percent			1.89%
Trust Preferred Securities [Member] | FCB Capital Trust III [Member] | Tenor Spread Adjustment [Member]
Debt Instrument [Line Items]
Preferred securities liquidation spread percent			0.26%
Trust Preferred Securities [Member] | Community First Statutory Trust I [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date							Dec. 26, 2032
Subordinated debenture basis spread on variable rate							3.25%
Preferred securities liquidation spread percent		3.25%
Trust Preferred Securities [Member] | Community First Statutory Trust I [Member] | Tenor Spread Adjustment [Member]
Debt Instrument [Line Items]
Preferred securities liquidation spread percent		0.26%
Trust Preferred Securities [Member] | American State Bank Statutory Trust I [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date							Sep. 15, 2035
Subordinated debenture basis spread on variable rate							1.80%
Preferred securities liquidation spread percent			1.80%
Trust Preferred Securities [Member] | American State Bank Statutory Trust I [Member] | Tenor Spread Adjustment [Member]
Debt Instrument [Line Items]
Preferred securities liquidation spread percent			0.26%
Maximum [Member]
Debt Instrument [Line Items]
Line of credit facility maximum borrowing capacity					$ 40,000,000
Minimum [Member]
Debt Instrument [Line Items]
Line of credit facility maximum borrowing capacity					$ 25,000,000
Agreement with Unaffiliated Financial Institution [Member]
Debt Instrument [Line Items]
Line of credit facility maximum borrowing capacity							$ 40,000,000
Federal Home Loan Bank Advances [Member]
Debt Instrument [Line Items]
Letter of credit							44,981,000	39,922,000
Line of credit facility maximum borrowing capacity							945,231,000	911,810,000
Line of credit facility additional borrowing capacity							684,768,000	770,711,000
Federal Home Loan Bank Advances [Member] | Securities [Member]
Debt Instrument [Line Items]
Line of credit facility maximum borrowing capacity							82,024,000	65,209,000
Federal Home Loan Bank Advances [Member] | Qualifying Loans [Member]
Debt Instrument [Line Items]
Line of credit facility maximum borrowing capacity							863,207,000	846,601,000
Federal Reserve Bank Borrowings [Member]
Debt Instrument [Line Items]
Line of credit facility maximum borrowing capacity							340,128,000	471,569,000
Pledged securities, fair value							9,620,000	155,934,000
Federal Reserve Bank Borrowings [Member] | Asset Pledged as Collateral without Right
Debt Instrument [Line Items]
Pledged loan outstanding balance							397,225,000	394,810,000
Federal Reserve's Bank Term Funding Program [Member]
Debt Instrument [Line Items]
Secured borrowings from this facility							$ 0	140,000,000
Debt instrument interest rate percentage							4.38%
Bank Stock Loan [Member]
Debt Instrument [Line Items]
Bank stock loan							$ 0	$ 0
Residential Mortgage-Backed Securities (Issued by Government-Sponsored Entities) [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date						Jun. 30, 2030
Debt instrument term							6 years	6 years 6 months
Subordinated notes aggregate principal amount						$ 42,000,000	$ 75,000,000	$ 75,000,000	$ 33,000,000
Subordinated notes commencement date						Dec. 30, 2020
Debt instrument interest rate percentage						7.00%
Subordinated notes description							From June 29, 2020, through June 29, 2025, the Company will pay interest on the notes semi-annually in arrears on June 30 and December 30 of each year, commencing on December 30, 2020, at a fixed interest rate of 7.00%. Beginning June 30, 2025, the notes convert to a floating interest rate, to be reset quarterly, equal to the then-current Three-Month Term SOFR, as defined in the Indenture, plus 688 basis points. Interest payments during the floating-rate period will be paid quarterly in arrears on March 30, June 30, September 30 and December 30 of each year, commencing on September 30, 2025.
Debt instrument, frequency of periodic payment							semi-annually
Residential Mortgage-Backed Securities (Issued by Government-Sponsored Entities) [Member] | SOFR plus [Member]
Debt Instrument [Line Items]
Subordinated notes commencement date						Sep. 30, 2025
Debt instrument, frequency of periodic payment						quarterly
Subordinated notes variable interest rate percentage						SOFR, as defined in the Indenture, plus 688 basis points
Government-Sponsored Residential Mortgage-Backed Securities [Member]
Debt Instrument [Line Items]
Residential mortgage-backed securities, fair value							$ 40,204,000	$ 47,282,000