Note 3 - Mergers and Acquisitions - (Details Textual) - USD ($)			12 Months Ended
	Mar. 01, 2022	Apr. 01, 2021	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Feb. 28, 2022	Mar. 31, 2021
Assets, Total			$ 6,584,550,000	$ 5,990,460,000
Financing Receivable, after Allowance for Credit Loss, Total			4,952,371,000	4,567,998,000
Deposits, Total			5,248,790,000	4,820,345,000
Business Combination, Acquisition Related Costs			236,000	4,808,000	$ 515,000
Liabilities, Total			5,940,291,000	5,409,979,000
Goodwill			88,391,000	88,543,000
Texas Citizens Bancorp [Member]
Assets, Total						$ 534,200,000
Financing Receivable, after Allowance for Credit Loss, Total						349,500,000
Deposits, Total						$ 477,200,000
Acquisition of SSW [Member]
Assets, Total							$ 3,600,000
Liabilities, Total							$ 2,300,000
Texas Citizens Bancorp [Member]
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares (in shares)	2,069,532
Business Combination, Acquisition Related Costs			$ 236,000	$ 5,200,000
Goodwill	$ 28,649,000
Texas Citizens Bancorp [Member] | Core Deposits [Member]
Finite-Lived Intangible Asset, Useful Life (Year)	10 years
Acquisition of SSW [Member]
Payments to Acquire Businesses, Gross		$ 7,300,000
Business Combination, Consideration Transferred, Liabilities Incurred		3,900,000
Goodwill		$ 6,500,000
Acquisition of SSW [Member] | Customer Relationships [Member]
Finite-Lived Intangible Asset, Useful Life (Year)		10 years
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles		$ 4,300,000