Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Income Taxes [Line Items]
Federal statutory tax rate	21.00%
Income tax expense	$ 11,480,000	$ 11,688,000
Effective tax rates on pre-tax income	17.70%	18.19%
Initial capital contribution commitment	$ 5,500,000
Initial contribution included in other assets	978,000	$ 131,000	$ 615,000
Leveraged loan, invest in other borrowings	$ 21,053,000
NMTC Investments [Member]
Income Taxes [Line Items]
Tax Benefit Percent of Qualified Investments	0.39
Investment related liabilities	$ 25,411,000	26,553,000	25,738,000
FFB Paris Investment Fund, LLC [Member]
Income Taxes [Line Items]
Loan investment	18,000,000	18,000,000	18,000,000
Leveraged loan, invest in other borrowings	$ 21,053,000	$ 21,053,000	$ 21,053,000